Tag Archives: How to calibrate the pyranometer?

Recalibrate pyranometer every 2 years……….

Recalibrate pyranometer every 2 years……….

It is advised to recalibrate Pyranometer after every two years as the sensitivity of pyranometer slightly changes. The recalibration provides the proof of correct irradiance measurements. It also increases the confidence on the stability of the equipment. On re calibrating pyranometer and recieving new sensitivity certificate , one gets sure of the reliability and correctness of the instrument.

There are two methods to calibrate pyranometers . Either using Laboratory sources (Indoor) or  using the sun (Outdoor) In both methods, the testing pyranometer and a reference standard pyranometer are exposed under the same conditions. ITC India Pvt Ltd has adopted the first method i.e. using Laboratory Sources and is explained below.   Both the pyranometers  reference and the pyranometer that has to be calibrated are exposed to a stabilized tungsten-filament lamp installed at the end of an optical bench. A practical source for this type of work is a 0.5 to 1.0 kW halogen lamp mounted in a water-cooled housing with forced ventilation and with its emission limited to the solar spectrum by a quartz window. This kind of lamp can be used if the standard and the instrument to be calibrated have the same spectral response. For general calibrations, a high-pressure xenon lamp with filters to give an approximate solar spectrum should be used. When calibrating pyranometers in this way, reflection effects should be excluded from the instruments by using black screens. The usual procedure is to install the reference instrument and measure the radiant flux. The reference is then removed and the measurement repeated using the testing instrument.

ITC India Pvt Ltd is calibrating pyranometer providing accurate and reliable results. So, do not delay in sending it to the Lab or calibrate  it on site. For any qyery write us t info@itcindia.org or visit www.itcindia.org 

ISO 9847 Calibration of Field Pyranometers

ISO 9847 Calibration of Field Pyranometers by Comparison to a Reference Pyranometer.

ISO 9847 Calibration of Field Pyranometers
ISO 9847 Calibration of Field Pyranometers

Are you looking for your pyranometer to be calibrated, ITC India Pvt Ltd has the facility to calibrate thermopile pyranometer at Lab and onsight. You are most welcome in ITC India Pvt Ltd for Pyranometer calibration. Either you can send the Pyranometer in the Lab or onsight calibration can be facilitated. Write to us at info@itcindia.org URL www.itcindi.org 

The calibration method is performed by our highly trained engineers and complies with type IIc Direct beam calibration of pyranometer as per international standard ISO 9847. 

Indoor calibration of field pyranometer is better as compared to outdoor in the following ways.

  • User control of test conditions
  • Results are independent of outdoor conditions
  • User convenience

The precision of the outdoor determination of the calibration factor of a field pyranometer is particularly dependent on sky conditions and solar elevation when performing measurements at low angles. Repeatability within any 21 points or more set of values of the same test scan performed at or near solar noon under stable irradiance conditions should be less than ± 0.5 % of the calibrated value of the instrument. If this requirement cannot be met, indoor calibration should be considered

To maintain performance, recalibration is usually recommended every two years, and a high-quality water-proof connector for the signal cable greatly simplifies the process.