DH Instruments GFS2102, Руководство по эксплуатации и обслуживанию, Страница: 194 / 206

GFS2102™ OPERATION AND MAINTENANCE MANUAL
© 2007 DH Instruments, a Fluke Company Page 178
Figure 114. External PRT adjustment tab.
7.5.7 INFRARED (IR) CYLINDER TEMPERATURE
ADJUSTMENT

PURPOSE
To view and adjust the output of the IR Cylinder temperature sensor.

OPERATION
If the LCM is displaying the main default screen, in GFS Tools use [TOOLS], [REMOTE
COMMUNICATIONS] to set up communications with the LCM and send the command
“ !KEY=15 ” twice, but if the LCM is displaying the TH probe screen send the command only
once. The LCM display will change to show a single temperature that is the output of the IR
cylinder temperature sensor. (see Figure 115).
When using the IR sensor, it is very important that the sensor be directed at the surface of
the GFS Reference Gas Cylinder as the infrared emissivity of the cylinder surface is what the
sensor is measuring. Other surfaces or materials will result in an invalid or inaccurate
measurement.
The IR sensor is NOT a high accuracy device and is only used to measure the cylinder
surface temperature to determine when moisture may be condensing on the surface, which
will have detrimental effects on system accuracy.
A one point verification against a temperature reference is all that is needed.
If a full adjustment is desired, at least two points should be selected within the range of the
sensor and encompass the range of measurements the sensor may encounter during normal
operation. This requires the use of an environmental chamber or oven capable of
temperatures above and below ambient, and unless this chamber can be place extremely
close to the GFS enclosure, the GFS sidewall column must be disassembled to remove the
IR sending unit mounted inside. The depressurized and vented GFS cylinder is then placed
in the chamber with the IR sensor pointed at the body of the cylinder and the reference probe
on or near the cylinder. When changing temperatures, a minimum of two hours of
temperature stabilization after reaching the temperature setting should be allowed before
taking a reading.