50461/GTEX MMC/1111
UTImeter Gtex MMC
44
10.10 Temperature verification
The temperature calibration curve is stored in the
sensor memory and cannot be modified. The
calibration is set once at the factory and do not
require subsequent adjustment.
Nevertheless it is recommended to check the
temperature accuracy once a year. A one point
check is enough to qualify the sensor.
10.10.1 Equipment required
-
A Dewar flask or any vacuum flask,
approximately 8 cm in diameter and 36 cm
deep.
-
Ice, preferably made from distilled water.
-
Water, preferably distilled and precooled.
10.10.2 Preparing the Ice Point bath
(1) Shave or crush the ice into small pieces,
avoiding direct contact with the hands or any
unclean object. The pieces shall be no more
then 5 mm.
(2) Fill the Dewar flask with the crushed ice and
add sufficient water to form a slush, just filling
the voids between ice particles but not
enough to float the ice.
(3) Insert the sensor, packing the ice gently about
it.
(4) Let it stand for half an hour to permit the
sensor temperature, the ice particles and the
water to equilibrate.
(5) As the ice melts it will be necessary to drain
off some water and add more crushed ice.
Gently stir the ice with the sensor periodically
to assist equilibration.
IMPORTANT NOTE
: Attention to detail during the
preparation of the Ice Point bath is critical
to the accuracy and quality of the offset
verification.
10.10.3 Checking the UTImeter
(6) After 30 minutes have elapsed, gently stir the
bath with the sensor again to ensure
complete equilibration of temperature.
(7) Switch on the UTImeter.
(8) Observe the reading. It should be
0.10 °C
(
0.20 °F) The temperature must be stable,
i.e. within
0.04 °C (
0.07 °F).
(9) If it is not OK, refer to section 11 "Trouble
shooting".
