Function Keys - Omega Engineering HH-21 User Manual

10. HOLD Hold Annunciator
This symbol will indicate that the instrument display is on hold.
11. SCAN Scan Annunciator
This annunciator will be displayed when the instrument is sequentially
viewing T1, T2 and T1-T2.

3. FUNCTION KEYS

The ON/OFF key turns the thermometer on or off. To turn the ther-
ON
mometer on, press the ON/OFF Key once. All the display annun-
ciators and segments should turn on momentarily (see Figure 2)
OFF
for visual checking. During this period the thermometer performs
internal diagnostics.
Following display test, if no input thermocouple is connected to
the unit, the display will indicate "OPEN".
Plugging a thermocouple into the appropriate TC connector will
give actual thermocouple temperature readings.
If the unit is turning on for the first time after installation of a new
battery, it will default to K-type thermocouples, and °F readings
with 0.1° resolution.
To turn the thermometer OFF, press the ON/OFF key a second
time.
The TEMPERATURE SCALE key selects whether temperature
°F
readings will be displayed in degrees Fahrenheit or degrees
Celsius. Upon initial power-up, the thermometer will display read-
°C
ings in degrees Fahrenheit. To display readings in degrees
Celsius, press the TEMPERATURE SCALE key. To change back
to degrees Fahrenheit, press the TEMPERATURE SCALE key a
second time.
NOTE: To obtain full accuracy, allow 1-2 minutes
after connecting a thermocouple plug, for
thermal setting.
NOTE:
• Key selection is retained during power off.
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