RegVault
Free trial

UN R134 Supplement 2 (01 series) · UNECE Regulation No. 134 (ECE R134) — Uniform provisions concerning the approval of motor vehicles and their components with regard to the safety-related performance of Hydrogen-Fuelled Vehicles (HFCV).

UN R134 — Supplement 2 to the 01 series of amendments

Supplement 1 → 2

Adopted at the WP.29 190th sessionEntry into force 2024-01-05
CompareRead full text
What changed
  • In Annex 5, paragraph 4.5., the measurement device must have a measurement response-time (t0 - t90) of less than two seconds. Before, the measurement response time had to be less than 300 milliseconds.
  • The measurement device must also have a resolution time of less than 300 milliseconds (sampling rate of >3.33 Hz).
  • In step (c) of paragraph 4.4., the power system is turned off after completion of the start-up process as defined by the manufacturer. Before, it was turned off after a lapse of one minute.
Why
  • No hydrogen analyser is on the market with a response time of less than 300 milliseconds.
  • The start-up process may last longer than one minute.

Q1What changed5 changes

Response time and resolution time of the measurement device (Annex 5, paragraph 4.5.)

The measurement device must have a measurement response-time (t0 - t90) of less than two seconds. Here, t0 is the moment of hydrogen concentration switching, and t90 is the time when 90 per cent of the final indication is reached. Before, the measurement response time had to be less than 300 milliseconds. New item (b) adds a resolution time of less than 300 milliseconds (sampling rate of >3.33 Hz).

The measurement device shall have a measurement response time of less than 300 milliseconds.The measurement device shall:
Have a measurement response-time (t0 - t90) of less than two seconds, where t0 is the moment of hydrogen concentration switching, and t90 is the time when 90 per cent of the final indication is reached.
1 more change in this group — open in Compare

Steps of the exhaust hydrogen measurement (Annex 5, paragraph 4.4.)

In step (c), the power system is turned off after completion of the start-up process as defined by the manufacturer. Before, the power system was turned off after a lapse of one minute. In both texts, measurement continues until the power system shut-down procedure is completed. In step (a), “shut-down” is now written “shut down”.

The power system is shut-downshut down;
After a lapse completion of one minutethe start-up process as defined by the manufacturer, the power system is turned off and measurement continues until the power system shut-down procedure is completed.
See every change side by side in Compare

Q2Why it changed

Proposed by
Expert from France
Working party
GRSP, 72nd session (December 2022)

Reasons

  • The proposal is meant to clarify the procedure and the characteristics of the measuring device used for the compliance test for the vehicle exhaust system. It is based on the ongoing work of UN GTR No. 13, Phase 2.

    Sources (2)
    “The proposal is meant to clarify the procedure and the characteristics of the measuring device used for the compliance test for the vehicle exhaust system.”
    “It is based on the ongoing work of UN GTR No. 13, Phase 2.”

  • The start-up process may last longer than one minute and may allow a “normal shutdown” not before one minute. Therefore, it would be more appropriate to turn off the system after completion of the start-up process.

    Sources (2)
    “However, the start-up process may last longer than one minute and may allow a “normal shutdown” not before one minute.”
    “Therefore, it would be more appropriate to turn off the system after completion of the start-up process.”

  • No hydrogen analyser is on the market with a response time of less than 300 milliseconds. A vacuum mass spectrometer can be used to observe hydrogen emissions with an appropriate time resolution. The pressure reduction from atmosphere to an appropriate vacuum level needs a thin capillary, which results in a travel time longer than 300 milliseconds. Therefore, the maximum measurement response time is updated to two seconds, and requirements on the resolution time were also added.

    Sources (4)
    “However, no hydrogen analyser is on the market with a response time of less than 300 milliseconds.”
    “The instrument which can be used for observing hydrogen emissions with an appropriate time resolution is a vacuum mass spectrometer.”
    “The pressure reduction from atmosphere to an appropriate vacuum level needs a respective length of a thin capillary which results in a travel time which is longer than 300 milliseconds.”
    “Therefore, the maximum measurement response time is updated to two seconds. Requirements on the resolution time of the measurement device were also added.”

Document trail

  1. 2022-09ProposalECE/TRANS/WP.29/GRSP/2022/15Proposal by the expert from France
  2. —Working party adoptsECE/TRANS/WP.29/GRSP/72Session report, para. 32
  3. 2023-03Sent to WP.29ECE/TRANS/WP.29/2023/53Text that GRSP sent to WP.29 and AC.1
  4. 2023-06WP.29 adoptsECE/TRANS/WP.29/1173Adopted at the 190th session (session report, para. 165)
  5. 2024-01-05In forceC.N.33.2024.TREATIES-XI.B.16.134UN depositary notification

Q3Who is affected

Vehicle manufacturer

  • No direct action for this role.

Component supplier

  • No direct action for this role.

Technical service / Approval authority

  • Use a measurement device with a measurement response-time (t0 - t90) of less than two seconds (paragraph 4.5.).
  • Make sure that the device has a resolution time of less than 300 milliseconds (sampling rate of >3.33 Hz).

See every change side by side

RegVault customers compare every version of UN regulations, read the consolidated text and download the PDF.

Start free trialSign in

ⓘ This report gives advice only. It is not legal or type-approval advice.

More UN R134 change reports

All UN R134 change reports