# Exhaust gas analysers · Annex XII · CO fraction, class I, rated operating conditions — Accuracy classes and maximum permissible errors for trade measuring instruments

For Exhaust gas analysers, annex is Annex XII; condition is CO fraction, class I, rated operating conditions; accuracy class is I; maximum permissible error is ± 0,06 % vol ± 5 %; scope or member state option is For each of the fractions measured, the maximum error value permitted under rated operating conditions according to point 1.1 of Annex I is the greater of the two values shown in Table 2. Absolute values are expressed in % vol or ppm vol, percentage values are percent of the true value, recorded from its source on 2026-09-01.

- **Instrument type:** Exhaust gas analysers _(verified: appears in its own passage below)_
- **Annex:** Annex XII _(verified: appears in its own passage below)_
- **Accuracy class:** I _(verified: appears in its own passage below)_
- **Condition:** CO fraction, class I, rated operating conditions _(our reading, not quoted from the source)_
- **Maximum permissible error:** ± 0,06 % vol ± 5 % _(verified: appears in its own passage below)_
- **Scope or member state option:** For each of the fractions measured, the maximum error value permitted under rated operating conditions according to point 1.1 of Annex I is the greater of the two values shown in Table 2. Absolute values are expressed in % vol or ppm vol, percentage values are percent of the true value. _(verified: appears in the quote below)_

## What the source says

> For each of the fractions measured, the maximum error value permitted under rated operating conditions according to point 1.1 of Annex I is the greater of the two values shown in Table 2. Absolute values are expressed in % vol or ppm vol, percentage values are percent of the true value. Table 2 MPEs | Parameter | Class 0 | Class I | CO fraction | ± 0,03 % vol ± 5 % | ± 0,06 % vol ± 5 % | CO2 fraction | ± 0,5 % vol ±5 % | ± 0,5 % vol ± 5 % | HC fraction | ± 10 ppm vol ± 5 % | ± 12 ppm vol ± 5 % | O2 fraction | ± 0,1 % vol ± 5 % | ± 0,1 % vol ± 5 %

## Where each value comes from

This source states these in separate places, so each value is shown with the passage it comes from.

### Instrument type

> ANNEX XII EXHAUST GAS ANALYSERS (MI-010) The relevant requirements of Annex I, the specific requirements of this Annex and the conformity assessment procedures listed in this Annex, apply to exhaust gas analysers defined below intended for inspection and professional maintenance of motor vehicles in use.

### Annex

> ANNEX XII EXHAUST GAS ANALYSERS (MI-010)

### Accuracy class

The source prints this value inside the passage below but does not name it there. The passage shows where it appears; what ties it to this record is the position on the page, not anything the passage says.

> For each of the fractions measured, the maximum error value permitted under rated operating conditions according to point 1.1 of Annex I is the greater of the two values shown in Table 2. Absolute values are expressed in % vol or ppm vol, percentage values are percent of the true value. Table 2 MPEs | Parameter | Class 0 | Class I

### Maximum permissible error

> For each of the fractions measured, the maximum error value permitted under rated operating conditions according to point 1.1 of Annex I is the greater of the two values shown in Table 2. Absolute values are expressed in % vol or ppm vol, percentage values are percent of the true value. Table 2 MPEs | Parameter | Class 0 | Class I | CO fraction | ± 0,03 % vol ± 5 % | ± 0,06 % vol ± 5 %

## Source

- https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32014L0032

Last verified: 2026-09-01. Review by: 2027-09-01.
Part of [Accuracy classes and maximum permissible errors for trade measuring instruments](https://referencesource.org/legal-metrology-accuracy-classes/).