US 11402311

I'll search for authoritative information on this patent number, including any 2026 CAFC docket activity.

Let me check the CAFC docket and litigation databases specifically.

Let me verify the full claim set and confirm whether any litigation exists.

US Patent 11,402,311 — Analyst Summary

Important caveat up front: I found no CAFC 2026 docket activity, no IPR, and no district-court litigation involving US 11,402,311 in the available search results. A targeted search for "11402311" CAFC appeal 2026 returned zero results, and broader litigation searches for the assignee turned up only the company's own corporate/credit filings — nothing tying this patent to an appeal or suit. I cannot affirmatively certify the absence of a docket entry from search results alone; the Federal Circuit's own docket (PACER/CAFC CM/ECF) would need to be queried directly to be certain. What I can say with confidence is that no 2026 CAFC proceeding for this patent surfaced.

---

Bibliographic Data (confirmed across sources)

---

Abstract

An arrangement for measuring a volume of a solid or liquid sample includes a first chamber for accommodating the sample; at least one second chamber connectable to the first chamber; a third chamber connectable to a gas supply source and connected to a gas entry path leading to at least one of the first chamber and the second chamber; a pressure sensor; plural gas paths comprising plural valves; a temperature equalization system configured to temper at least the first chamber, the second chamber and the third chamber to substantially a same temperature, wherein the gas paths and the valves are arranged and connected such as to allow, filling gas out of the third chamber into at least one of the first chamber and the second chamber, and measuring a pressure in at least one of the first chamber and the second chamber.

---

Plain-Language Overview of the Independent Claim(s)

Independent claim 1 — the apparatus ("arrangement"):

This is a gas-expansion pycnometer (an instrument that measures a sample's volume by displacing gas, used to derive true density). The core inventive addition is a third, "acclimation" chamber that sits between the external gas supply and the measurement chambers.

In plain terms, the claim requires:

1. A first chamber that holds the sample being measured.
2. At least one second chamber that can be connected to the first chamber (the reference/expansion chamber).
3. A third chamber connected to a gas supply and feeding a gas entry path toward the first and/or second chamber.
4. A pressure sensor.
5. Multiple gas paths and valves connecting the above.
6. A temperature equalization system that holds the first, second, and third chambers at substantially the same temperature.
7. Where the plumbing and valves let you fill gas from the third chamber into the first and/or second chamber and measure the pressure there.

The point of the third chamber is thermal: gas from an external cylinder normally enters at a temperature different from the instrument's controlled operating temperature (e.g., 5–50 °C), which forces a long wait for the gas to equilibrate before a stable pressure reading. By pre-conditioning ("acclimating") the gas in a third chamber that shares the same thermal control as the sample and reference chambers, the gas is already at the right temperature when it enters, shortening equilibration/measurement time and improving accuracy. The specification frames this as the remedy for the prior art's "prolonged measurement time" problem.

Likely second independent claim (method of manufacturing): The specification states that a "method for manufacturing an arrangement for measuring a volume of a solid or liquid sample" is also provided as a separate aspect. I would expect a corresponding independent method claim in the issued patent, but I could not verify the exact claim numbering or the full accepted claim set from the sources retrieved — treat the existence/number of that method claim as unconfirmed rather than asserted.

Dependent claims (verified from the published claim set): claim 2 (temperature equalization via a metal assembly in thermal contact with all three chambers and the valves), claim 3 (third-chamber volume 0.1×–100× a chamber volume), claim 4 (metallic high-surface-area filler in the third chamber: mesh, fleece, sintered structure, etc.), claim 5 (Peltier tempering equipment + insulation), claim 6 (three-part bolted metal assembly with stacked flat mating surfaces), claim 7 (first/second gas supply paths with first/second valves), claim 8 (third/fourth measurement paths with third/fourth valves to the pressure sensor), and further dependent claims covering fifth/sixth vent paths and valves, the controller and its two measurement modes, unidirectional "input-side leak-tight" valves, seventh/eighth paths and valves, and the processor/electronic-storage calibration aspect.

---

Notes on Reliability

• Title, inventors, assignee, application number, dates, and abstract are confirmed by multiple independent sources (Google Patents full text, onscope, Justia, FreePatentsOnline) and are consistent.
• The claim-1 language quoted above is taken from the published application US 2021/0156778 A1 (which prints the same claims; the issued patent's claim 1 reads identically per the patent full text provided).
• Uncertainty flagged: (a) exact issued-claim count and the precise numbering of any method claim; (b) the negative finding on 2026 CAFC docket activity, which is a search limitation rather than a verified "no litigation" conclusion.

I'll search for litigation involving US patent 11402311 across patent litigation databases.

Let me search more targeted litigation databases.

Let me search specific litigation databases directly.

Litigation Search: US Patent No. 11,402,311

Patent identified (literal reading): US 11,402,311 B2 — "Pycnometer with acclimation chamber"; application US 16/694,931; filed 2019-11-25; granted 2022-08-02; current assignee Anton Paar QuantaTec, Inc.; inventors Enrique Gadea Ramos and Freddy Quesada. (Source: https://patents.google.com/patent/US11402311/en)

Result: No litigation found

Based on the searches I was able to run (general web and patent-litigation-focused queries keyed to the exact number "11402311" / "11,402,311" and to the assignee Anton Paar QuantaTec), I found no U.S. district court case, Court of Appeals for the Federal Circuit appeal, Section 337/ITC investigation, PTAB proceeding (IPR/PGR), or foreign court action that is confirmed to assert or challenge US 11,402,311.

I want to be explicit about the limits of this conclusion, per your instructions not to fabricate:

1. The searches returned no case record tied to this patent number. Results for "11402311" were dominated by unrelated hits (e.g., a UK company-registration number "11402311" for White & Bazell Ltd) — I am not auto-correcting or conflating those; they are simply unrelated identifiers that happen to share the digit string.
2. I could not complete direct database lookups. My attempts to query Unified Patents' litigation portal, CourtListener/RECAP, Docket Alarm, and PACER-specific searches for the exact number were cut off before returning results. Those are the authoritative sources you named, and I could not fully verify against them in this session. A negative finding under these conditions is weaker than a negative finding from a direct PACER/Docket Navigator query.
3. No PTAB proceeding found. Nothing indicated an IPR or PGR petition against US 11,402,311. For context, the patent is recent (granted August 2022) and the assignee appears to be an operating instrument company (Anton Paar QuantaTec) rather than a litigation-focused NPE, which is consistent with a low assertion profile.

Related (but NOT confirmed) activity — flagged for caution

• Chinese litigation, case (2024)苏07民初50号 (filed 2024-04-03, Suzhou Intermediate Court, case status "审理中"/pending): plaintiffs listed are 安东帕有限公司 (ANTON PAAR GMBH) and 安东帕康塔科技公司 (ANTON PAAR QUANTATEC INC.). This confirms Anton Paar QuantaTec is an active plaintiff in at least one patent suit filed in China in 2024, but the source does not identify the patent(s) asserted, so I cannot confirm — and do not represent — that US 11,402,311 is involved. It may involve the sibling "bidirectional pycnometer" family (e.g., WO2021105794), which is a different patent.
• Rudolph Research Analytical Inc. v. Anton Paar OptoTec GmbH, No. 3:17-cv-04273 (D.N.J., filed 2017-07-12) — Anton Paar was a defendant, but the patent-in-suit was U.S. 6,717,665 (polarimeter), and the case predates US 11,402,311. Not relevant to this patent.
• The earlier Anton Paar/QuantaTec patent-portfolio listings I reviewed contain no litigation entries for US 11,402,311.

Bottom line

As of the information available to me, there is no known litigation involving US Patent No. 11,402,311. If you need a definitive answer, I recommend a direct, exact-number search of PACER (via Docket Alarm / CourtListener RECAP), Unified Patents' litigation caselist, and Docket Navigator, restricted to the literal number "11,402,311" — and a parallel check of the patent's "Litigation" tab on Google Patents, which was not retrievable in this session.

I'll verify the structured "no proceedings" finding against live sources before writing.

Let me run a few more targeted checks on PTAB databases and related family patents.

PTAB / AIA Trial Analysis — US 11,402,311 B2 ("Pycnometer with acclimation chamber")

Note on the record: The structured "PTAB proceedings on file" block supplied in this prompt is the canonical source, and it states that the USPTO Open Data Portal returns no AIA trial proceedings for this patent as of the most recent ingest. I ran independent web searches to try to falsify that default (petitioner-side, assignee-side, and art-side queries), and they returned no petition, no institution decision, no FWD, and no PTAB docket entry touching US 11,402,311. The finding below is therefore a confirmed-by-multiple-sources negative, subject to the verification caveat at the end.

---

Proceedings overview

Total AIA trial proceedings on US 11,402,311: 0 — 0 active, 0 claims invalidated, 0 claims sustained, 0 settled, 0 institution denials (no petition has ever been filed, so there is nothing to deny).

The bottom line for a defendant is the opposite of a hardened patent and the opposite of a dead patent: every claim of US 11,402,311 — claims 1 through the last dependent claim — is completely UNTESTED at the PTAB. There is no FWD, no certificate of cancellation, no estoppel, and no PTAB claim construction to inherit. No defensive aggregator has taken this patent on, and there is no public signal that any accused infringer has ever bothered to file. If you are holding a demand letter, you hold a patent whose validity has never been adjudicated in any forum — which cuts both ways (see Strategic summary).

Important: the analysis template for this task includes illustrative examples of the form "claims 1-5 have been canceled — if your demand letter cites them, the troll has no case." No such cancellation exists for this patent. Do not let any boilerplate to that effect survive into a client-facing memo.

---

Per-proceeding detail

None. There are no proceeding numbers to report, and I will not invent any. Every requested field (type, filing date, status, panel, grounds, institution decision, FWD, settlement, appeal) is inapplicable because no IPR####-#####, PGR####-#####, or CBM####-##### number exists for this patent.

---

Strategic summary

Claim status — all UNTESTED. No claim of US 11,402,311 has been canceled, confirmed, or construed at the PTAB. Claims 1–N (including the apparatus claim 1 covering the first/second/third-chamber arrangement with the shared temperature equalization system, and the dependent claims directed to the metal-assembly temperature equalization system, the 0.1×–100× third-chamber volume ratio, the high-surface-area metallic filler, Peltier tempering, the three-portion bolted metal assembly, the supply/measurement/vent paths, the controller with two bidirectional measurement modes, unidirectional input-side-leak-tight valves, and the processor/electronic-storage calibration aspect) stand exactly as issued on 2022-08-02. Practical consequence: there is no PTAB-narrowed claim set to work around, and no PTAB-construed term to rely on. A defendant's invalidity case starts from zero — including the cost and the full § 102/§ 103 burden of building it from scratch.

Estoppel landscape — clean. Because no IPR has resulted in a final written decision under § 318(a), § 315(e)(1) and § 315(e)(2) estoppel do not attach to anyone. No petitioner, real party in interest, or privy is barred from raising any ground. Every printed-publication and patent ground under §§ 102/103 remains fully available, in the Office and in district court, to every party — and there is no risk that a prior failed or partially successful IPR has foreclosed your best art. The corollary risk runs the other way: if you file and lose on some claims, you create estoppel for yourself and your privies on those claims, and you hand the patent owner a validity win on a preponderance standard.

Pattern signals — all negative. No repeat petitioner, no serial petitioning, no patent-owner appeal activity, and no Unified Patents or other defensive-aggregator involvement surfaced (a targeted Unified Patents IPR pycnometer Anton Paar search returned nothing relevant). One historical data point worth knowing but not to be over-read: the assignee's corporate predecessor, Quantachrome Corporation, appears in an old matter styled Quantachrome Corp. v. Micromeritics, Fed. Cir. No. 00-1416 (filed 2000) — that is roughly two decades before this patent existed, involves different technology and different patents, and I did not verify its substance or outcome; treat it as background color on the corporate family, not as litigation history of US 11,402,311.

Why the absence matters here, and why it is not automatically good news. The usual inference is "well-asserted patents eventually attract IPRs." In this case the absence more likely reflects the market: the assignee, Anton Paar QuantaTec, Inc. (Boynton Beach, FL; formerly Quantachrome, acquired by Anton Paar GmbH in 2018) is an established analytical-instrument manufacturer selling these pycnometers commercially, not a non-practicing entity running an assertion campaign. There is no public record of US 11,402,311 being asserted against anyone. So the realistic defensive posture is not "this patent is battle-hardened" and not "this patent is dead" — it is: an untested, commercially-practiced instrument patent in a narrow technical field (pycnometry / gas-displacement true-density measurement), with no PTAB track record in either direction.

A related-family caution. US 11,402,311 is not alone in the family. The same inventors' US application 16/694,615, filed the same day (2019-11-25) on a "Bidirectional pycnometer," has a German counterpart that granted as DE 11 2020 005 793 B4 (assignee Anton Paar QuantaTec Inc.), and its German specification cites a prior-art set highly relevant to the present patent's field: US 2017/0010196 A1, US 2017/0030817 A1, US 5,074,146 A, US 6,036,296 A, EP 0 720 011 A1, and CN 203 981 234 U. US 2017/0010196 A1 and US 2017/0030817 A1 are also the two references the US 11,402,311 specification itself discusses as prior art. I could not confirm a granted US patent number for the "Bidirectional pycnometer" case, and I could not confirm that it has been through any PTAB proceeding either — but if you are mapping risk in this space, assume the assignee may hold more than one pycnometer patent and scope your invalidity search across the family rather than against US 11,402,311 in isolation. Whether the ancestor WO 2021/105793 A1 showing "Ceased" on Google Patents has any bearing is a PCT-route legal-status artifact, not a validity signal, and I would not draw conclusions from it.

---

Recommended next steps

If you were hoping to rely on an existing PTAB outcome — you cannot. There is no FWD to quote, no disposition to link, and no canceled claim to point at. Do not represent otherwise to a court or a client.

If you are a defendant and want to file an IPR:

• Watch the § 315(b) clock first. The one-year bar runs from service of a complaint alleging infringement. Because there is no litigation on record, the clock is presumably not running for anyone yet — but confirm against the actual docket rather than assuming.
• Front-load the art search against the specification's own admitted prior art. The patent explicitly distinguishes US 4,095,437 A, US 2017/0030817 A1, and US 2017/0010196 A1, and the specification is candid that gas is admitted to the sample chamber "at a temperature that is different from the entire arrangement temperature," producing the long equilibration times the invention claims to solve. That candid framing of the problem is a favorable starting point for a § 103 obviousness theory built on a primary pycnometer reference plus a secondary thermal-conditioning/pre-heating reference — the classic combination for a "precondition the gas before it enters the measurement volume" invention. The strongest dependent-claim anchors to attack independently are the ones with concrete structural limitations: the third-chamber-volume ratio (claim 3), the high-surface-area metallic filler (claim 4), and the three-portion bolted metal assembly (claim 6).
• Note the § 315(e) asymmetry: filing first and winning gives you broad estoppel protection; filing first and losing on even one claim cements it for the patent owner in district court.
• PGR is foreclosed. The § 321 post-grant window closed nine months after grant (i.e., by roughly 2023-05-02); only IPR under §§ 102/103 on patents and printed publications remains available.

For anyone who needs to confirm the negative authoritatively (search engines can miss recently filed petitions that ODP has not yet indexed):

• PTAB End-to-End (E2E) trial search: https://ptab.uspto.gov/ — search by patent number 11,402,311
• USPTO PTAB API (bulk, structured, best for confirming a true null): https://developer.uspto.gov/ptab-api/
• Patent full text (authoritative for citations and claim text): https://patents.google.com/patent/US11402311/en
• Patent Center (prosecution history, fee/status events): https://patentcenter.uspto.gov/
• CourtListener / RECAP (for any § 315(b) predicate complaint): https://www.courtlistener.com/?q=11402311

Verification caveat. A null result from web search and an ODP ingest is strong but not a certificate. The authoritative confirmation is a patent-number query on PTAB E2E and the PTAB API endpoints above. If you need that for a filing or an opinion, run it directly rather than relying on this summary.

Cross-reference flag: This is consistent with the previously generated section for this patent, which found no PTAB, no IPR, and no 2026 CAFC activity. I found no contradiction between that section and the canonical structured data. The one thing to correct going forward is that the earlier section flagged as unconfirmed whether a method-of-manufacturing independent claim exists in the issued claim set — that remains unverified, and it also remains untested at the PTAB regardless of how the claims are numbered.

I'll research the assignment record for this patent before writing. Let me query multiple sources.

Let me search the assignment databases and corporate records more specifically.

Let me try to pin down the specific recorded assignment reel/frame and check for any later transfers.

Assignment & Ownership Analysis — US 11,402,311 B2 ("Pycnometer with acclimation chamber")

Sourcing note (read first): The only ownership event I could positively confirm from the retrieved material is the inventor-to-assignee assignment recorded 2020-01-15, which Google Patents lists in the legal-events table for this patent. I was not able to retrieve the reel/frame number or the correspondent of record — the USPTO Assignment Center record did not surface in the searches I ran before the tool limit was reached. Accordingly, no reel/frame is stated below; I will not invent one. Where I say "unverified," treat it as a genuine gap, not a negative finding. Verification path: Assignment Center or assignment.uspto.gov, search by patent number 11402311 / app 16/694,931.

---

Inventors

Unusual-pattern check: Not present. There is no evidence of the inventors departing the assignee within 12 months of the 2019-11-25 filing. To the contrary, Gadea Ramos resurfaces as a named inventor on the sibling "Bidirectional pycnometer" family filed ~2020-10-30 (WO 2021/105794; DE 11 2020 005793 B4), which is consistent with continued employment, not a fire-sale precursor. Both inventors assigned to the corporate assignee, the standard operating-company pattern.

---

Original assignee

• Entity on the issued patent: Anton Paar QuantaTec, Inc., 1900 Corporate Drive, Boynton Beach, FL 33426 (Florida profit corporation, document no. P95000010165, FEI/EIN 11-2161663, incorporated 1995).
• Line of business: Design, manufacture, sale, and service of analytical instrumentation for characterizing porous materials and powders — gas/vapor/water sorption analyzers, gas-displacement pycnometers, mercury and capillary-flow porosimeters, and related lab services. NAICS 334516 (Analytical Laboratory Instrument Manufacturing).
• Does it ship a product embodying the claims? It ships gas pycnometers, which is precisely the claim-1 class of apparatus (e.g., the Ultrapyc product line). I flag that I did not verify, claim-by-claim, that any specific shipping model practices the "acclimation chamber" limitation — treat the product-embodiment point as high-confidence but not element-by-element confirmed.
• Current status: Operating. Not dissolved, not in bankruptcy. A 2025 Florida Profit Corporation Annual Report was filed (signature dated 2025-03-25), listing officers Alfred Freiberger (Chairman/Director), Georg Cortolezis-Supp (President/Secretary/Director), Reinhard Eberl (VP/Director), Rick Steinberg (Treasurer).
• Ownership context (corporate, not a patent assignment): The company was formerly Quantachrome Corporation and was acquired by Anton Paar GmbH (Graz, Austria) on 2018-02-09, then renamed Anton Paar QuantaTec, Inc. It operates as a subsidiary of the Austrian parent. This acquisition predates the patent's 2019-11-25 filing, so it is background, not a recorded assignment against this patent.

---

Assignment timeline

The chain contains exactly one recorded assignment — the standard inventor conveyance. There are no post-issuance assignments; the patent has run out its life to date with the original corporate assignee. (That negative result is itself the substantive finding: the operating company still owns it.)

• 2020-01-15 (executed date not confirmed) / recorded 2020-01-15 — Reel/frame NOT RETRIEVED (see sourcing note)
  • Conveyance: Assignment of assignors' interest ("ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS)")
  • Assignor: Enrique Gadea Ramos (individually); Freddy Quesada (individually)
  • Assignee: Anton Paar QuantaTec, Inc., Boynton Beach, FL
  • Correspondent: Not retrieved / unverified. Recurrence in this chain or elsewhere could not be tested, so no repeat-correspondent flag can be raised or cleared.
  • Context: Ordinary inventor-to-employer assignment — the inventors conveyed their rights to the company that filed and prosecutes the application; not a fire-sale, reorg, securitization, or transfer-to-asserter.

No other records (no security agreement, merger, change of name, license, release, or correction) were found for this patent in the retrieved material.

---

Timeline diagram

timeline
    title Ownership of US 11402311
    2018 : Quantachrome acquired by Anton Paar
         : Renamed Anton Paar QuantaTec
    2019 : Application filed 2019 11 25
    2020 : Inventor assignment recorded 2020 01 15
         : PCT family filed Oct 2020
    2022 : Patent issued 2022 08 02
         : No further assignments recorded

---

NPE / troll-pattern signals

---

Verdict

Insufficient data (only the original assignment) — but read this as a negative finding for NPE activity, not an information vacuum about the owner. Per the rubric, the "only the original assignment" case falls in this bucket; substantively, the sole recorded event is the inventor-to-employer conveyance recorded 2020-01-15 to Anton Paar QuantaTec, Inc., and the patent has since stayed with that operating manufacturer (former Quantachrome; Anton Paar GmbH subsidiary since 2018-02-09). No shell entity, no known asserter, no cascading transfers, no bankruptcy, no privateering, and no pre-litigation transfer appear anywhere in the chain. The one residual uncertainty — the reel/frame and correspondent of record, which I could not retrieve — is what keeps this from being a clean "operating-company, non-asserting" call, since the correspondent is the single most diagnostic field for confirming the absence of an NPE hand behind the scenes.

Verify at: https://assignmentcenter.uspto.gov/ (search patent no. 11402311) — the retrieved record is also reflected in the Google Patents legal-events table at https://patents.google.com/patent/US11402311/en.

I'll research the patent citations for US 11,402,311. Let me search for the authoritative citation records.

Let me look specifically for the citation list on the USPTO and Google Patents records.

Prior-Art Analysis — US 11,402,311 B2 ("Pycnometer with acclimation chamber")

Scope and honest limits of this search

Before the analysis, a transparency note — because it materially affects reliability:

1. Confirmed target. The number 11402311 resolves unambiguously to US 11,402,311 B2, "Pycnometer with acclimation chamber," app. US 16/694,931, Anton Paar Quantatec, Inc. No similar-number records (e.g., 11,402,341 / 11,402,301 / 11,402,313) were substituted.
2. What I could NOT retrieve. I was unable to pull the face-of-patent "References Cited / U.S. Patent Documents" list from the USPTO full-text (PatFT/PatentCenter) or from the Google Patents "Citations" panel in the available results. That means the enumeration below reflects the references the specification itself identifies and discusses as prior art, plus a check for examiner-cited art — not a verified reproduction of the examiner's (56) list. If the issued patent's front page cites additional references (very common in this art unit), I could not enumerate them here and will not fabricate them.
3. No §102 anticipation found. None of the references below discloses the distinguishing limitation of claim 1 — the third chamber combined with a temperature equalization system tempering all three chambers (first, second, third) to substantially the same temperature. Accordingly, each reference is discussed as background / potential §103 art, not true §102 anticipation.

---

The three prior-art references cited within US 11,402,311

Source for all quoted characterizations: the patent full text itself, https://patents.google.com/patent/US11402311/en (background section).

1. U.S. Pat. No. 4,095,437 A

§102 analysis: This reference discloses the classic two-volume gas-expansion architecture — a sample cell, a reservoir, and pressure-based volume/density computation. It does not disclose a third, separate acclimation chamber (as distinguished from a mere reservoir/conduit), and it does not disclose a temperature equalization system configured to temper three chambers to substantially the same temperature. Therefore it does not anticipate claim 1 (or its dependents) under §102. Its possible relevance is limited to establishing the general state of pycnometry and, at most, as §103 background for the reservoir/plumbing elements.

---

2. US 2017/0030817 A1

§102 analysis: This reference addresses the same technical problem (true-density via gas expansion) and adds a variable expansion volume. It is, however, silent on any third acclimation/conditioning chamber and silent on a temperature equalization system holding three chambers at the same temperature. The "volume modification member" of US 2017/0030817 is a different concept from the claimed third chamber (which the specification expressly says is "different from a mere gas conduit" because it holds the entire gas charge for a measurement). No anticipation of claim 1. Again, potential §103/background only — and note the examiner could combine it with a thermal-control teaching, but that teaching is absent here.

---

3. US 2017/0010196 A1

§102 analysis: This reference is cited for its lid/sealing arrangement — i.e., the sample-chamber closure. In US 11,402,311 the lid is a described (Fig. 1, element 104; Fig. 2, element 204/grip 212/hook 216) but unclaimed feature; note that none of the claim-1 limitations recite a lid. So US 2017/0010196 does not anticipate claim 1 and, at most, bears on the general sample-chamber construction. It contains no third acclimation chamber and no three-chamber temperature equalization system.

---

Bottom line

The single limitation that none of the cited references teaches or suggests — and which therefore carries the novelty of US 11,402,311 — is the (a) dedicated third chamber sized to hold the full gas charge, in combination with (b) a temperature equalization system asserting (per claim 1) "substantially a same temperature" across the first, second, and third chambers. That is the element to police in any §102 rejection; the three references above are properly background/§103 material, not anticipatory art.

---

Flagged uncertainties (per the "do not fabricate" rule)

• I did not obtain the examiner's actual (56) "References Cited" list for US 11,402,311. The three references above are those the specification discusses as prior art. There may be additional U.S. patent documents cited on the patent's face that I could not retrieve; I have not invented any.
• Exact issue date of US 4,095,437 A was not verifyable from the retrieved sources, so I have not stated a specific day. The publication dates for the two 2017 U.S. application publications (2017-01-12 and 2017-02-02) are given as they appear for those serial-prefixed publication numbers.
• If you can supply the "(56) References Cited" block from the issued front page (or the USPTO PatentCenter document), I can complete the full reference-by-reference table and run a precise element-by-element §102/§103 mapping against the actual cited art.

I'll ground this analysis by pulling the prior-art references cited on the patent's face/specification and checking for additional analogous art.

Let me pull the sibling/related patents and search for additional analogous art on gas pre-conditioning in pycnometry.

Obviousness Analysis — US 11,402,311 B2 under 35 U.S.C. § 103

Building on the earlier bibliographic/claim-overview section; not repeated here. One correction to that section: the published claim set confirms the method claim is claim 19 ("A method for manufacturing an arrangement for measuring a volume of a solid or liquid sample…"), resolving the uncertainty flagged earlier — see https://patents.justia.com/patent/20210156778 (claim 19).

---

1. Reference discrepancy to flag before analysis

The '311 specification cites "U.S. Pat. No. 4,095,437 A" as disclosing a porous-polymer pycnometer. My search for that exact number returned no document; the reference whose disclosure matches the '311 specification's description word-for-word ("A computer calculates the density of the sample… The gas reservoir is joined to a gas cylinder") is US 4,095,473 A, "Pycnometer," Gulf Oil Corporation — https://www.freepatentsonline.com/[4095473](/patent/4095473).html and https://patents.justia.com/patent/4095473.

Per the strict-ID rule I am not auto-correcting the number. I treat "4,095,437 A" as literally cited, but all substantive disclosure mapping below is to 4,095,473, and I flag the mismatch as an unresolved citation-integrity issue that should be checked against the granted patent's front page (which was not retrievable in the excerpt provided).

---

2. Legal framework and level of ordinary skill

Governing law: AIA § 103 (effective for a 2019 filing). KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) supplies the rationales; Graham v. John Deere supplies the factual inquiries. Prior-art status of the two MicrotracBEL publications is § 102(a)(1) (published 2017-02-02 and 2017-01-12, both before the 2019-11-25 filing).

Level of ordinary skill (POSITA): a bachelor's degree in physics, mechanical engineering, or instrumentation, plus 2–5 years in gas pycnometry / gas-sorption or true-density instrumentation; conversant with the ideal-gas (Boyle–Mariotte) relation, dead-volume calibration, valve/manifold sequencing, and the thermal sensitivity of pressure-based volume measurement. This is a mature, incremental engineering field — which lowers the non-obviousness bar for small structural additions.

Scope of the claim term "third chamber" — a claim-construction vulnerability. The specification states the gas entry path "including a gas container (also referred to as a third chamber)" may be held at the same temperature as the first and second chambers (see '311 §"the gas entry path including a gas container…"). If "third chamber" is read to cover the ordinary gas cylinder/container 181, then any temperature-controlled pycnometer with a thermally-equilibrated supply vessel reads on claim 1, materially enlarging the prior-art exposure. This ambiguity should be resolved before any § 103 conclusion is finalized.

---

3. Element-by-element mapping of claim 1

Conclusion: the entire novelty of claim 1 over the cited art reduces to (i) a third chamber that is separate from the sample and expansion chambers, and (ii) a temperature equalization system that slaves that third chamber to the same temperature as the other two. Everything else is squarely in the cited art. That is a narrow gap, and it is bridged by the specification's own prior-art admissions (below).

---

4. The specification's own prior-art admissions (KSR "known problem" evidence)

The '311 specification concedes the state of the art in terms that are effectively a roadmap for the rejection:

"In the prior art there is no control of the temperature of the gas before it is introduced into the sample or reference chambers. The gas enters the analysis chamber at the time of measurement with ambient temperature. The equilibration of the gas takes a significant amount of time which means that in the state of the art, the full advantage of the thermal control cannot be leveraged." ('311, Description)

"Conventionally known pycnometers may have problems regarding prolonged measurement time. In particular, it has been observed that long equilibration times are necessary…" ('311, Technological Background)

These admissions establish three facts dispositive to motivation: (a) the problem (gas-source thermal disturbance → long equilibration) was known; (b) instrument-level thermal control was already known; (c) the only unmet need was bringing the incoming gas to the instrument's temperature. Under KSR, a "problem recognized in the field" plus a "predictable solution" is the classic case of obviousness.

---

5. Proposed § 103 combinations

Combination A (primary) — '473 in view of '817 and/or '196, further in view of the '311 admissions

Primary: 4,095,473. Discloses the full pycnometer architecture: sample cell, known-volume gas reservoir charged from a supply cylinder, manometer, a computer storing calibrated volumes of "the gas reservoir and the empty sample cell… from prior calibrations," an automated valve sequence, and a gas thermocouple feeding the computer for temperature correction. This teaches (a) the charge-intermediate-volume-then-admit sequence, and (b) that the field already regarded gas temperature as an error source requiring compensation.

Secondary: '817 and/or '196. Teach that the sample chamber and the expansion chamber are both formed in a single block (20), with all openings on a common block surface — i.e., the art already co-locates measurement chambers in one common thermal mass. '817 expressly frames this architecture as solving an accuracy problem ("a further increase in accuracy of measurement").

The combination: a POSITA seeking to shorten equilibration time would (1) recognize from '817/'196 that co-locating chambers in one block is an accuracy-improving architecture, (2) recognize from '473 that the incoming gas must be charged through an intermediate known volume, and (3) extend the single block to include a third, dedicated chamber holding the full gas charge, bores connecting it to the sample/reference chambers, and tempering equipment for the block. The result is claim 1.

Motivation to combine (articulated):

• Same field / analogous art — all three references are true-density-by-gas-displacement instruments (CPC G01N 9/00–9/26), same problem space.
• Recognized problem — the '311 admissions show the industry knew the equilibration delay was thermal in origin.
• Predictable result — thermal pre-conditioning of a gas before it enters a temperature-controlled volume is elementary heat transfer; the outcome (shorter equilibration, better accuracy) is exactly what one would expect.
• Market/throughput pressure — the specification itself frames the benefit in throughput terms.

Combination B — '817 or '196 as primary, in view of '473

Reverse the order: take '817/'196's single-block, lid-sealed, accuracy-focused pycnometer as the base structure; use '473's intermediate gas reservoir + thermocouple/correction teaching to add a thermally-equilibrated dosing chamber in the block. Same result, and arguably the better combination because '817/'196 already supply the "metal assembly harboring the chambers" structure that the '311 claim 2 requires, leaving only the third-chamber-plus-tempering gap.

Combination C — either A or B plus a secondary reference for the heat-transfer expedients

Depends claims 4–5 (high-surface-area metallic filler; Peltier tempering + insulation) and claim 2 (metal-assembly thermal contact with valves and gas-path portions) are ordinary mechanical-design expedients. The specification itself concedes as much:

• Metal wool/mesh as a heat-exchange surface insert: conventional regenerator/heat-exchanger art (metal wool, sintered media, knitted mesh are ubiquitous heat-transfer surfaces). The spec's own text calls the metal mesh a means "to increase the surface participating in the heat transfer."
• Peltier tempering + insulation is standard instrument practice.

I could not retrieve a specific pycnometry reference teaching a thermally-slaved intermediate dosing chamber in the time available, so Combination A/B rests on the cited art plus the specification's admissions and general knowledge. That is a legitimate but less airtight evidentiary posture than a clean two-reference showing — see §8.

---

6. Dependent claims — obviousness notes

---

7. Secondary-consideration counterweights (and why they likely fail)

The patentee's best rebuttal is unexpected results — the specification asserts the threshold for declaring equilibration can be tightened to 0.3 mTorr/min, and frames a "pycnometer with highest accuracy." Under KSR, however, "a particular application of a known technique" yielding a predictable improvement is not non-obvious merely because it is beneficial; here the improvement is the direct, expected consequence of eliminating the gas-temperature transient. Absent comparative data showing a nonlinear/super-additive effect, this is unlikely to rebut the prima facie case. No commercial-success, copying, or long-felt-but-unmet-need evidence was located in the available materials.

---

8. Weaknesses of the § 103 case (and where the patentee would attack)

1. The crux limitation is genuinely absent from the cited art. None of 4,095,473, 2017/0030817, or 2017/0010196 recognizes that the incoming gas temperature is the error source, and none discloses a third chamber separate from, and in addition to, the expansion chamber that is thermally slaved to the sample/reference chambers. In '473 the reservoir is not a third, dedicated acclimation volume — it performs the expansion-measurement function.
2. Alternative-solution / teaching-away argument. '817 attacks the identical accuracy problem by a different mechanism — variable expansion-chamber volume via an insertable/withdrawable capacity-changing member. A patentee can argue the art taught in a divergent direction, away from adding a fixed-volume acclimation chamber.
3. Holistic-charge limitation (claim 3). The requirement that the third chamber hold all gas for a complete measurement (so no unrestrained gas enters during the run) is a functional-sizing constraint, not a bare numerical range; the patentee will argue it is not shown or suggested.
4. No verified pycnometry reference for the heat-transfer expedients. I found no retrieved reference teaching a metal-mesh-filled, thermally-slaved dosing chamber in a pycnometer; claims 4–5 therefore lean on general-knowledge/analogous-art reasoning, which is defensible but more vulnerable than a documentary two-reference showing.
5. "Third chamber" ambiguity cuts both ways. If the term is construed narrowly (dedicated acclimation chamber only), § 103 is harder to prove; if construed to embrace the ordinary gas container, § 103 becomes much easier. The claim-construction outcome drives the result.

---

9. Related-application considerations that must not be conflated with § 103

• US 11,169,014 B2, "Bidirectional pycnometer," filed the same day (2019-11-25), same assignee (Anton Paar Quantatec), inventors Gadea Ramos/Thomas/Thaler (https://patents.google.com/patent/[US11169014B2](/patent/US11169014B2)/en). It discloses the same first/second/third/fourth gas-path-and-valve architecture, the two measurement modes, the unidirectional input-side-leak-tight valve orientation, the metal assembly with gas paths as bores, and the eighth purge valve. Because it shares a filing date with the '311 application, it is not § 102(a)(1) art, and to the extent it is § 102(a)(2) art it is excludable under § 103(c)(1) as commonly owned. It should not be relied upon in a § 103 rejection. It is, however, strong contextual evidence that the manifold/valve architecture claimed in '311 claims 7–12 and 14–17 was known work in the same laboratory at the same time — and it raises a separate obviousness-type double patenting exposure worth flagging to the client.
• JP 7631647 B2 (the '311 family member) and JP 7400182 B2 (the sibling's family member) confirm the family and cite the same MicrotracBEL documents plus US 5,074,146 ("gas comparison pycnometer" for determining solid volume and checking accuracy) — see https://patents.google.com/patent/JP7400182B2/en. US 5,074,146 was not cited in the '311 specification as provided and I could not verify its content in this session; it is a candidate additional reference for a broader search but I will not assert what it discloses.

---

10. Bottom line

Claim 1 is vulnerable to § 103 on the combination of US 4,095,473 (full charge-reservoir-and-cell pycnometer with pressure/temperature sensing, computer, stored calibration volumes, vented cells) in view of US 2017/0030817 and/or US 2017/0010196 (sample and expansion chambers co-located in a common block, motivated by measurement accuracy), further in view of the '311 specification's own admissions that (a) gas entering at ambient temperature causes the long equilibration delay and (b) instrument thermal control was already known. The only true gap — a dedicated, thermally-slaved third chamber sized to hold the entire gas charge — is bridged by the recognized problem plus predictable heat-transfer practice; claims 2 and 4–10 fall with it, and the processor/calibration-storage aspect is affirmatively disclosed in '473. The patentee's strongest defenses are (1) a narrow construction of "third chamber," (2) the alternative-solution argument rooted in '817's variable-volume expansion chamber, and (3) the holistic-charge sizing limitation of claim 3.

Reliability caveats: the cited "4,095,437 A" could not be retrieved literally (best match 4,095,473 — flagged, not corrected); no dedicated pycnometry reference teaching a thermally-equilibrated dosing chamber was found, so parts of Combinations A–C rest on analogous-art/general-knowledge reasoning that should be buttressed with a targeted search before the rejection is finalized; and the litigation/docket findings from the earlier section stand unchanged.