 The narrow-angle radiometer is used to measure the total radiant energy
incoming from one direction and bounded within a small viewing angle (total intensity).
From this instrument, basic information is obtained on the thermal radiation
characteristics of flames provided total intensity measurements are carried out at various
positions across the flame.
The probe consists of a straight
tube of 35 mm internal diameter with a minimum length requirement of one meter which is
water cooled by means of a surrounding jacket. The probe is introduced into the furnace
and directed towards the flame layer during the measurements. A nitrogen purge is applied
in order to prevent contamination of the probe. The receiver unit which is temperature
controlled by means of a separate cooling water circuit is located on its other end away
from the furnace. The receiver contains a spherically-concave, rhodium plated mirror 60 mm
in diameter which.focuses the beam of radiation passing through the tube onto a small
receiver disc mounted on a thermistor cell. In order to eliminate, as far as possible, the
effect of ambient temperature on the electrical signal, a second thermistor which is not
irradiated is placed near the thermistor exposed to radiation. The two form branches of a
Whetstone bridge circuit. They are shielded against natural convection in the large volume
of the receiver unit by means of a small CaF-window which offers very little absorptivity
to thermal radiation.
The narrow angle radiometer
must be calibrated using a blackbody furnace. Zero check can be made by means of a shutter
mounted into the receiver unit which stops the radiation beam.
VENDOR: IFRF Research Station b.v.
Would you be interested in :
- getting more information about
this measurement equipment?
Please contact us:
IFRF Research Station B.V.
P.O. Box 10 000
1970 CA IJmuiden
The Netherlands
email: sales@ifrf.net
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