Calibration-Round-Robin CaRo (since 1993)

1993 - 2016 realized by Adolf Kuhner AG, Birsfelden, Switzerland

for determination of the explosion characteristics of dusts

CaRo24 - Progress

Calibration-Round-Robin CaRo24 announcement

After our previous world-wide round robin tests

CaRo93: 77 apparatuses CaRo05:   98 apparatuses CaRo15: 131 apparatuses CaRo21: 125 apparatuses
CaRo96: 68 apparatuses CaRo07:   77 apparatuses CaRo17: 144 apparatuses CaRo22:   50 apparatuses
CaRo98: 63 apparatuses CaRo09:   90 apparatuses CaRo18:   41 apparatuses CaRo23: 130 Apparaturen
CaRo00: 69 apparatuses CaRo11: 122 apparatuses CaRo19: 127 apparatuses
CaRo03: 93 apparatuses CaRo13: 112 apparatuses CaRo20:   41 apparatuses

we will carry out on schedule the new calibration round robin "CaRo24".


Determination of the explosion characteristics using standard test methods:

Pmax maximum explosion overpressure
Kmax product-specific constant
LEL/MEC lower explosion limit New
LOC limiting oxygen concentration New
MIE minimum ignition energy
and calibration of the relevant test apparatus.


According to international standards the 20-l-apparatus and the 1-m3-vessel for the determination of Pmax and Kmax and the apparatus for determination of the minimum ignition energy must be calibrated at regular intervals (at least every 12 months or following any significant maintenance or repair). For this purpose, an international calibration round test (calibration round robin = CaRo) has been carried out periodically since 1993.

EN 13821 Determination of minimum ignition energy of dust/air mixtures
EN 14034-1 Determination of max. explosion pressure Pmax …
EN 14034-2 Determination of max. rate of explosion pressure rise (dp/dt)max …
EN 14034-3 Determination of the lower explosion limit LEL …
EN 14034-4 Determination of the limiting oxygen concentration LOC …
ASTM E2019 Minimum Ignition Energy MIE of a Dust Cloud in Air
ASTM E1226 Explosibility of Dust Clouds
ASTM E1515 Minimum Explosible Concentration MEC of Combustible Dusts
ASTM E2931 Limiting Oxygen Concentration LOC of Combustible Dust Clouds
EN ISO/IEC 80079-20-2 … Material characteristics. Combustible dust methods

Calibration method:

The mean values of the explosion indices, measured by the participating laboratories, will be calculated as reference values. All apparatuses, with results lying within the given tolerance range, meet the calibration requirements and will receive a calibration-certificate from us. Based on experience with previous round robin tests, we are certain that we will be able to discover and rectify the cause of any errors with installations producing results deviating significantly from the reference values.

Our service:

The test dust will be selected, homogenized, packed under nitrogen and mailed by us. All test results are continually evaluated and will be published in the internet in a protected area exclusively for CaRo24 participants. This allows you to pre-check your own test results. After expiry of the test period, a detailed overall evaluation with the calculation of the standard values and the associated tolerance band is carried out by Cesana AG. Those apparatuses which meet the calibration requirements will receive a certificate. All results will then be summarized in tabular form (anonymously) and mailed to the participants.
New  We offer the option of receiving interim certificates from us based on the results obtained (at least 10 per apparatus) in urgent cases, e.g. as part of an audit.


CaRo24 participants will get a free upgrade to software KSEP 7.1 and MIKE 3.5 / MIKE 4.0 (for MIKE3 CAN, MIKE4)


The fee for participation depends on the number of apparatuses:

order no. calibration of: price in Swiss Francs CHF
SP9101 1 apparatus 2‘600.-
SP9102 2 apparatuses 3‘960.-
SP9103 3 apparatuses 4‘910.-
SP9104 4 apparatuses 5‘620.-
The price includes packaging, but not the delivery-, customs- and VAT charges (value added tax).

Test dust:

The amount of test dust depends on the type of apparatus:

  • 20-l-apparatus, MIE-apparatus: 1kg each
  • 1m3-vessel: 10kg (SP9111 extra costs = CHF 2‘650.-) Pmax, Kmax, MEC/LEL
  • 1m3-vessel: 15kg (SP9112 extra costs = CHF 3‘975.-) Pmax, Kmax, MEC, LOC


Mailing of test dust: starting end of April 2024
Deadline for receipt of test results: end of November 2024
Final report of CaRo24, certificates: January 2025

The reports of the CaRo tests will be published here.

CaRo - Final Reports

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Realization and Distribution