Green Mark Sensor calibration

It is all over the world, everyone is talking about sustainable greenmark movement. Developed and developing nations are embarking on a journey to reduce carbon foot print and move towards clean and green sustainable energy efforts to save our environment.

As an active partner for this movement, since the year 2007, ISOLAB has started to calibrate various NTC thermistor (such as 1kΩ, 5kΩ, 10kΩ and 30kΩ) greenmark temperature sensors accurately with the lowest measurement uncertainty of 3 mK (0.003°C). ISOLAB’s contribution of calibration is more than 5,000 greenmark sensors.

ISOLAB’s calibration standards and every measurement aspect complies with ASHRAE Guidelines 22:2008 and Singapore Standard SS 591:2013 (Singapore Standard for Long Term Measurement of Central Chilled Water System Energy Efficiency). ISOLAB follows the requirements of the below mentioned clauses of SS591:2013.

Singapore Standard SS 591: 2013, Page 17 Clause(s)

3.1.4.1. The maximum allowable uncertainty of the temperature measurement system shall be +0.05°C over the working range of 0°C to 40°C. The uncertainty of the temperature measurement shall include the uncertainty of the entire chain of the temperature measurement i.e; the temperature sensor, transmitter, wiring, data acquisition system etc.

3.1.4.2. Each temperature sensor shall be individually calibrated against a measurement standard with maximum uncertainty rating of +0.01°C.

3.1.4.3. Fixed points calibration method is one of the recommended options to be used in the calibration of the temperature sensors. It is recommended that the following references be used during the calibration:

  • a) Water triple point at 0.01°C
  • b) Standard platinum resistance thermometers (SPRT) with temperature controlled bath at 15.00°C; and
  • c) Gallium fixed point cell at 29.765°C

Next to NMC Singapore, ISOLAB is the only commercial laboratory that follows International Temperature Scale (ITS 90) derived fixed-point calibration method for greenmark temperature sensors at Water triple point (TPW) at 0.01°C and Gallium fixed point (GMP) at 29.765°C

The industry experts and customers are highly confident and sure about ISOLAB’s quality and uncertainty assurances during calibration of greenmark temperature sensors.


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