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Calibration of analytical measurands

Our calibration service in the field of analytical measuring instruments covers a diverse and complex range of different measurands and measuring instruments, which are used in almost all branches of industry.

An extensive and fully equipped analytical calibration laboratory is part of Testo Industrial Services. We carry out calibrations in the field of gas analyses and other chemical analyses completely independent of manufacturers. Gas analysis includes the calibration of flue gas meters, gas detectors and gas leak and refrigerant testers. Calibration of pH, conductivity and frying oil testers are among the other chemical analyses. Here we calibrate your pH meters and conductivity meters with our high-precision equipment.

Our DAkkS accreditation in the analytical laboratory covers chemical and medical measurands in the area of conductivity and pH values, as well as in the area of flue gas. Take a look at our accreditation certificate.

Your advantage: Our competence

  • Smallest measurement uncertainty for DAkkS calibrations in the pH range from 0.03 pH
  • Smallest measurement uncertainty for DAkkS calibrations in the conductivity range from 0.3 %
  • Smallest measurement uncertainties for DAkkS-accredited calibrations in the flue gas sector from 0.03 % by volume
  • Calibration of CO-, CO2-environment measuring instruments

Our innovations:

  • Full DAkkS accreditation for conductivity and pH calibrations
  • Germany's first DAkkS-accredited laboratory for flue gas calibrations
  • Calibration of CO measuring instruments

Insight into our analytical calibration laboratory

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Gas analysis

Gas analyses are carried out in many industries and sectors to investigate the composition of gases and gas mixtures. Testo Industrial Services has a fully equipped measuring station for the calibration of your flue gas and gas analysis measuring instruments.

With the help of reference materials or test gases whose composition is known very precisely and traceable within certain limits, a wide range of concentrations of gas mixtures such as carbon monoxide, oxygen or nitrogen monoxide can be calibrated. All portable electrical devices for measuring combustion parameters that are certified in accordance with DIN EN 50379-1 are considered to be calibratable.

Ambient CO, CO2 measuring devices are used to monitor indoor air quality. We can calibrate these in accordance with ISO and DAkkS. Your CO2 measuring devices are calibrated in the analytical laboratory at the measuring points 0 ppm, 1000 ppm and 5000 ppm. Your CO measuring devices are calibrated in the analytical laboratory at the measuring points 0 ppm and 80 ppm.

The calibration device for gas leak testers, gas analyzers, gas detectors and refrigerant leak testers can be used to perform calibrations at 1 vol.% for methane (CH4) and for refrigerants (R143a) at various leak rates of 3 g/a, 5 g/a and 10 g/a.  The calibration of your CO2 measuring instrumentsis carried out in the analytical laboratory at the measuring points 0 ppm, 1000 ppm and 5000 ppm. All portable electrical devices for the measurement of combustion parameters which are certified according to DIN EN 50379-1 are considered to be capable of calibration.


For gas analyses we are specialized in the following measuring instruments:

  • Flue gas measuring devices
  • CO probes, CO measuring devices for ambient measurement
  • CO2 probes, CO2 measuring devices for ambient measurement
  • Refrigerant and glass leak testers
    (e.g. testo 316-4, R134a, CPS Leak-Seeker, INFICON D-Tec, Select Inficon, Rothenberger, 200HC, ...)
  • Gas detectors (e.g. Dräger X-am® 2500, MSA Altair, Sewerin, Afriso)

Overview of the reference gases in the flue gas system

Testo Industrial Services is able to perform a flue gas calibration with several predefined test gases with different concentrations:

  • O2: 1,5 Vol%, 2,5 Vol%, 5,0 Vol% 
  • CO: 100 ppm; 300 ppm, 400 ppm, 700 ppm, 5000 ppm,  
  • NO: 150 ppm, 300 ppm 
  • CO2: 17 Vol.% , 38,5 Vol% 
  • NO2: 100 ppm 
  • CH4: 5000 ppm, 10000 ppm (1 Vol%) 
  • H2S: 200 ppm 
  • SO2: 100 ppm 

Other chemical analyses: LF, pH, TPM

In addition to gas analyses, the analytical calibration laboratory of Testo Industrial Services also includes other chemical analyses. This area includes the measurands pH, conductivity and the calibration of frying oil testers.

Messung der Leitfähigikeit

Conductivity measurements

The measurement of conductivity is used, among other things, for the control of the purity of water, for example also of deionized water in cooling circuits but also in connection with glucose oxidase for blood sugar measurement.

At our facilities, we can calibrate your conductivity meters at 1.3; 5; 15; 100; 700; 1413 μScm or 100 mS/cm. In this case, the electrical conductivity is determined by means of a resistance measurement.

Kalibrierung pH Messgeräten

pH measurements

The measurement of the pH value provides a measure of the acidic or basic character of an aqueous solution and is used in many areas: 

  • Food analysis / quality control
  • Research and development
  • Water analysis
  • Medicine

The measuring instruments for measuringthepH value can be calibrated at pH 2, pH 4, pH 7, pH 9, pH 10, pH 11.

Ermittlung TPM-Wert

Frying oil measurement

Frying oil testers are used for quality assurance (determination of the degree of contamination) of frying oil. A frying oil tester measures the proportion of so-called "Total Polar Materials" (TPM) in the oil and indicates this as a percentage. Measuring instruments for measuring the TPM value can be calibrated at ± 4% TPM as well as ± 24% TPM. Frying oil testers have their field of application in:

  • Large kitchens, canteens, large catering companies
  • Food monitoring, food producers
  • Large restaurants & fast food chains

Common manufacturers

The list of common manufacturers of pH and conductivity measuring instruments as well as frying oil testers, which we can operate, is extensive. The following overview offers a small excerpt:

  • WTW GmbH / Xylem Analytics
  • Greisinger GHM Group
  • Hanna Instruments Deutschland GmbH
  • Endress+Hauser Group Services AG
  • Ahlborn Mess- und Regelungstechnik GmbH
  • Extech Instruments
  • Hach Lange GmbH
  • Knick Elektronische Messgeräte­ GmbH & Co. KG
  • Thermo Fisher Scientific Inc.
  • Testo SE & Co. KGaA
  • VOLTCRAFT / Conrad Electronic AG

Success stories

We support you with your requirements and work towards your goals. Here you will find an overview of our most successful customer projects:



Calibration in the analytical laboratory


Our know-how summarized for you. Either find knowledge from our subject matter experts on the topic of Analytical Calibration directly in our Knowledge-Centre or dive into an appropriate technical article on your topic. 

Our scope of services for you

Our scope of services includes standard ISO calibrations as well as accredited DAkkS calibrations. Here you will find an excerpt of the services we offer in our laboratories and at your site.

Calibration object Gas analyses: Flue gas measuring instruments, CO meters, CO2 probes, (Ex) gas detectors, refrigerant and gas leak testers, gas analyzersCalibration DAkkS-accredited*On-site calibration
With different test gas concentrations: CO, H2, NO, NO2, O2, H2S, SO2, CH4, CO2
CO probes using 2 to 3 predefined measuring points
Refrigerant and gas leak tester using a test gas with defined pressure
Calibration object Chemical analyses: pH meters, conductivity meters, refactor meters (ESS), frying oil testersCalibration DAkkS-accredited*On-site calibration
ph measuring instruments by an electrical simulation of the sensor signal.
ph measuring chains using reference solutions
Conductivity meters at different conductivity measuring points
Conductivity and pH buffer solution from Testo (4.01pH / 7.00pH)
Conductivity measuring systems for applications in pure and ultrapure water
Frying oil tester using capacitive measurements (± 4% TPM / ± 24% TPM)
Refractometer with display

* in the lab

To read

Take a look at our topic-specific brochures and learn more about calibrating your measuring instruments.