ThermoWorks 9141 HART SCIENTIFIC FIELD DRY-WELL TEMPERATURE CALIBRATORS - Manual (Page 23)

6 General Operation
6.1 Changing Display Units
The 9141 can display temperature in Celsius or Fahrenheit. The temperature
units are shipped from the factory set to Celsius. To change to Fahrenheit or
back to Celsius there are two ways:
1 - Press the “SET” and “UP” simultaneously. This will change display units.
2 - Press the “SET” key three times from the temperature display to show
Un= C
Press the “UP” or “Down” key to change units.
Press “SET” to store changes.
6.2 Switching to 230V Operation
The 9141 is switchable from 115 VAC to 230 VAC 50/60 Hz. Switching the
voltage can change the calibration, so the unit should be calibrated after
changing the input voltage.
To change from 115 VAC to 230 VAC:
• Unplug the unit.
• Lay the unit down on its side.
• With a small straight slot screwdriver remove the fuse holder located on
the rear panel. Replace the two fuses (10 amp 250 V) with 5 amp 250V
fuses.
• Replace the fuse holder with the “230V” in the display window.
• Using the same straight slot screwdriver, move the heater switch to dis-
play “230V”. See the rear panel drawing in Figure 2 on page 15.
NOTE: If the heater switch and the fuse holder do not both read 230V when
complete, the unit will either not heat or only heat at a fraction of its capacity.
If not done properly, the unit could become damaged and void the calibration
and warranty. Use 10 amp fuses for 115V and 5 amp for 230V only. DO NOT
PLUG THE UNIT INTO 230 V IF THE HEATER SWITCH AND FUSE
HOLDER READ 115. THIS WILL CAUSE THE FUSES TO BLOW AND
MAY DAMAGE THE INSTRUMENT.
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6 General Operation
Changing Display Units