LumaSense Technologies MIKRON M345X12 - Manual (Page 14)

M345X12 Blackbody Manual Operation 14
3.5 Calibration
The M345 has a precision RTD monitoring the emitter temperature. A separate measuring well
allows insertion of a secondary measuring device for calibration to a customer supplied standard
RTD. The well is 4.2mm diameter and about 26mm deep.
The easiest way to calibrate is to view uncorrected temperature along with the customer provided
primary standard RTD that is used in the secondary well on the blackbody emitter plate.
3.5.1 Calibration Method
There are two distinctly different methods of calibration, each with its own application advantages.
These methods are described as follows:
Thermometric Method:
In this method, the surface temperature of emitting surface is precisely measured and controlled.
The sensor is an ultra precision platinum RTD that closely monitors the temperature of the emitting
surface. This method is widely used in aerospace industries, since it provides an easy method of
periodically verifying calibration. A deep hole with a 0.165” (3.5mm) diameter is provided for
customer insertion of calibration RTD. Knowledge of emitter emissivity characteristic is needed for
correct radiated energy computation.
Radiometric Method:
In this method, calibration is based on the energy radiated from the emitter surface at a desired
spectral band. This emitted radiation is compared with the primary blackbody calibration source
with emissivity of greater than 0.998, using a precision transfer standard. The advantage of this
technique is that the characteristic of emitter emissivity has already been calibrated into the system.
An apparent emissivity of greater than 0.995 can be achieved. Recalibration or field calibration
using this technique is more difficult and elaborate since highly precision primary blackbody
calibration sources and transfer standard are needed.
This blackbody was calibrated:
[ ] radiometrically [ ] thermometrically.
3.5.2 Calibration Certificate
The certificate of calibration of your blackbody source has been enclosed as a part of this manual or
under separate cover. This certificate contains valuable information including traceability number to
NIST. Please observe recommended date of next calibration.