Watlow Series 935B User’s Manual
37
Calibrating the 935B
Thermocouple Input Field Calibration Procedure
Equipment Required:
• Type “J” Reference Compensator with reference junction at 32°F/0°C, or Type “J” Thermocouple Calibrator set at
32°F/0°C.
• Precision millivolt source, 0-50mV min. range, 0.01mV resolution.
Set Up:
1.
Connect 100-240V
Å
(ac) to Terminal 7 and Terminal 8.
2.
Connect the millivolt source to Terminal 1 negative and Terminal 2 positive.
3.
Apply power to the unit and allow it to warm up for 15 minutes.
Move to the Calibration Menu:
1.
Press
.
and
,
simultaneously for 3 seconds.
2.
Press
.
or
,
until
[CnFG]
is displayed.
Press and hold
ß
– press
.
or
,
to select
[`YES]
, then release
ß
.
3.
Press
.
or
,
until
[`TAG]
is displayed.
Press and hold
ß
. Press
.
or
,
8 times (display shall be blank).
Calibration: (Thermocouple)
1.
Press and hold
ß
,
.
, and
,
simultaneously for 3 seconds until
[TR50]
is displayed.
2.
Set the mV source to 50.00mV
Î
(dc). Allow 10 seconds for sources to stabilize. Press and hold
ß
. Press
.
or
,
until
[`YES]
appears. Release
ß
.
3.
Press
,
-
[Tc00]
shall be displayed.
4.
Set the mV source to 0.00 mV
Î
(dc). Allow 10 seconds for sources to stabilize. Press and hold
ß
. Press
.
or
,
until
[`YES]
appears. Release
ß
.
5.
Press
,
.
[``Tc]
shall be displayed.
6.
Set the MV source to 0.00 mV (if using a temperature compensator). Set calibrator to 32°F/0°C.
Allow 10 seconds for sources to stabilize.
Press and hold
ß
. Press
.
or
,
until
[`YES]
is displayed. Release
ß
.
Calibration: (RTD)
Equipment Required:
• Precision Resistance Box with 0.01
Ω
Resolution.
1.
Remove thermocouple wires from Terminal 1 and Terminal 2.
2.
Connect S2 to terminal 1. Connect S1 to Terminal 2.
3.
Press
,
.
[R`15]
shall be displayed.
4.
Set the Decade box to 15.00
Ω
(allow 10 seconds for sources to stabilize). Press and hold
ß
. Press
.
or
,
until
[`YES]
appears. Release
ß
.
5.
Press
,
-
[R380]
shall be displayed.
6.
Set the decade box to 380.00
Ω
(allow 10 seconds for sources to stabilize). Press and hold
ß
. Press
.
or
,
until
[`YES]
appears. Release
ß
.
7.
Press and hold
.
and
,
for 3 seconds to Exit calibration menu.