Owner manual

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 100-240VÅ (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 50.00mVÎ (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 mVÎ (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 0.01Ω 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 15.00Ω (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 380.00Ω (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.