Operating Instructions
Landcal Blackbody Source
Type P80P
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INTRODUCTION
The LANDCAL blackbody source type P80P is a variable temperature, portable black body radiation source
designed for use at temperatures up to 80°C (175°F).
The source is a primary standard black body for the high precision calibration of radiation thermometers over
the range -10 to 80°C (15 to 175°F). When the set point temperature is reached, the output from the thermometer
under test is compared with the temperature of the source as measured by an optional Platinum resistance
thermometer whose calibration is traceable to National Standards.
When used in conjunction with the Platinum resistance thermometer which is supplied complete with a UKAS
(United Kingdom Accreditation Service) calibration certificate, high precision is obtained. Alternatively the
source can be used in three other ways.
(i)
If traceability to National Standards is required to a larger value of uncertainty a UKAS certificate of
calibration for the source can be supplied. The relationship between the indicated temperature on the
controller and the radiance temperature as measured by a secondary standard radiation thermometer is
reported.
(ii)
The temperature of the source can be measured by using a radiation thermometer of traceable calibration.
This method of calibration can be described as calibration by comparison with a standard radiation
thermometer. This method of calibration usually results in the most accurate as errors due to temperature
gradients and non-black body conditions are eliminated.
(iii)
If traceability to National Standards is not required, the source can be used without any certification. From
previous work the temperature, as shown on the controller indication, has been found to agree with the
radiance temperature to within ±4K (±8°F).
The source provides a wide angle target which makes it ideal for use with both fixed installation and portable, hand-
held thermometers.
To make the lining up of LAND fixed installation radiation thermometers simpler, an optical bench assembly is offered
as an optional extra. When the source is stood on the optional transportation case, the bench to mid target dimension
equals that of the optical bench assembly.
