ISO 17025

Calibration (ISO 17025 certification)

ISO 17025 calibration is a common name for a calibration performed in an external laboratory, that is ISO 17025 accredited.
ISO 17025 is a specific standard that regulates requirements of competence of testing and calibration laboratories.
Calibration performed in ISO 17025 accredited laboratory is recognised in all European Union countries.

Main features

  • ISO 17025 is an world recognised standard for calibration laboratories
  • Analysers calibrated in ISO 17025 labs are permitted to perform environmental protection measurements
  • Every sensor is certified in 4 points (4 different gas concentrations)
  • Newly ordered analyser can be certified within 14 working days (production lead time prolongs for this time)

madur calibration

The madur calibration is the very essential one. This is when the analyser is „told” how to interpret electrical signal generated by electrochemical, infrared or any other sensor, when introduced to a concentration of measured gas → µV to ppm or % of gas.
Every gas analyser or sensor must be calibrated with the use of reference gases.
Reference gas of a known concentration is applied to apparatus, that reacts with a proportional electrical signal.
Calibration is a process of assigning this electrical signal to the concentration of the applied reference gas.
Calibration requires, depending on the type of sensor, from 2 to up to 10 calibration points (so 2-10 different reference gas concentrations).
During the madur calibration process, another important matter is established, i.e. cross-sensitivity of sensor to alien gases.
More information about cross-sensitivity and calibration can be found in madur FAQ.
After the madur calibration, the device is fully operational and ready to use.

ISO calibration

On rare occasions, e.g. when a device is used for measurement of emissions of industrial objects (and based on that a fine for environment pollution is calculated) the device must hold a valid calibration certificate, issued by authorised, accredited laboratory.
madur co-operates with accredited laboratory, therefore it is possible to deliver any device with the mentioned ISO 17025 certificate.
ISO 17025 differs from madur calibration: this is in fact a verification if the analyser measures properly.
As in case of madur calibration, a reference gas of a known concentration is applied to analyser, but here, it is only verified, if the result presented by the analyser (expressed in ppm or %) corresponds to the concentration of the reference gas, provided by the accredited laboratory's personnel.
ISO 17025 certificate is issued only when the device measures properly, i.e. when validation with reference gases is successful.
ISO 17025 calibration is required (by local authorities) to be annually renewed.
To be certain of successful certificate renewal, we encourage to order madur to verify and if necessary to correct the analyser prior to the ISO 17025 validation.
We offer a complex calibration service, i.e. analyser’s verification in our lab and afterwards, accreditation of analyser in ISO 17025 lab.

Client can choose up to 4 points from the available range for each gas.
Successful accreditation is proven with the suitable certificate issued by ISO 17025 lab.

1. Gases available for ISO 17025 certification

ISO 17025 calibration is performed in 4 points per sensor. Points can be selected from the ranges presented in table below.

Symbol Gas Low range High range
O2 Oxygen 3% ÷ 15%
CO Carbon monoxide 4 ppm ÷ 100 ppm 400 ppm ÷ 5 000 ppm
CO2 Carbon dioxide 1 000 ppm ÷ 5 000 ppm 1,2% ÷ 14%
NO Nitric oxide 2 ppm ÷ 100 ppm 400 ppm ÷ 2 000 ppm
NO2 Nitrogen oxide 4 ppm ÷ 20 ppm
SO2 Sulfur dioxide 3 ppm ÷ 15 ppm 60 ppm ÷ 1 000 ppm
CH4 Methane 3 000ppm - 25 000ppm


Please write below the new quantity.

New value:


General information

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