Red Lion TLA - Manual (Page 12)

Millivolt Calibration (CAL)
Connect precision millivolt source with an accuracy of 0.03% to terminals #8
(-) & #9 (+). Cold Junction or RTD ohms calibration MUST be performed after
millivolt calibration.
Thermocouple Cold Junction Calibration (CJC)
This procedure must be performed AFTER an accurate mV calibration.
1. Exit Factory Service Operations (continually press P until “End”), and return
to Normal Display Mode.
2. Connect a thermocouple probe of known accuracy to the TLA (Types T, E, J,
K, and N only). Select the probe type used in Configure Module 1.
3. Connect a reference temperature probe to the measuring end of the TLA
thermocouple probe. The two probes should be shielded from air movement
and allowed sufficient time to equalize in temperature. (As an alternative, the
TLA thermocouple probe may be placed in a calibration bath of known
temperature.)
4. Compare TLA display with reference temperature probe (or calibration bath).
If the displayed TLA temperature does not equal the reference probe
temperature, calculate the CJ error as follows:
CJ Error = reference probe temperature - displayed TLA temperature
5. Enter Factory Service Operations Module (9-FS).
RTD Ohms Calibration (RTD)
This procedure must be performed AFTER an accurate mV calibration.
Connect one leg of precision resistance (accuracy of 0.1 ohm) to terminals #9
and #10 together, and the other leg to #8.
12
6.0 C
ALIbRATION
When re-calibration is required (generally every two years), this procedure
should be performed by qualified technicians using appropriate equipment.
Equipment source accuracy of 0.03% or better is required.
The procedure consists of: applying accurate mV signals, setting the
thermocouple cold junction temperature, and applying precision resistance,
among others. Allow a 30 minute warm-up period before starting this procedure.
Do not use thermocouple wire for the millivolt or RTD ohms calibration.
This procedure may be aborted by disconnecting power to the TLA before
exiting the configuration mode. The existing calibration settings remain in
affect.
Note: After completing any of the calibration sequences, the TLA defaults the
input sensor type to thermocouple type “J” (tc-J). Be sure to set input sensor
for proper type.
Note: The TLA must be restored to normal display mode before any data is
stored.
Not required if only using TC input. This procedure can only be performed
AFTER an accurate mV calibration.
yes/no RTD resistance calibration
rtd
Not required if only using RTD input. This procedure can only be performed
AFTER an accurate mV calibration.
yes/no Thermocouple cold junction
temperature calibration
CJC
Calibration required for both RTD and TC input. If this procedure is performed,
the cold junction temp or RTD ohms calibration procedures in turn must be
completed.
Calibrate instrument.
yes/no
48
Millivolt calibration
Enter function code
CAL
CodE
DESCRIPTION/ COMMENTS RANGE PARAMETER DISPLAY
Factory Service Operations - Calibration (9-FS)
Wait 10 seconds, press P. Apply 14.0 mV
Wait 10 seconds, press P.
Wait 10 seconds, press P.
Apply 56.0 mV
Apply 42.0 mV
StP5
StP4
StP2
Wait 10 seconds, press P. Apply 28.0 mV StP3
Apply 0.0 mV StP1
DESCRIPTION/ COMMENTS ACTION DISPLAY
Wait 10 seconds, press P.
Cold Junction
Temperature
CJC
DESCRIPTION/ COMMENTS PARAMETER DISPLAY
Note: If the initial value for CJC is not within
the range of 15°C to 40°C, enter 25.0° for
CJC and repeat the Cold Junction Calibration
procedure.
Observe the indicated cold junction
temperature. Add the calculated CJ Error to
the displayed value. Enter the sum as the new
value for CJC. Exit 9-FS and repeat step 4.
Wait 10 seconds, press P. rtd2
Wait 10 seconds, press P. rtd1
DESCRIPTION/ COMMENTS ACTION DISPLAY
Connect 0.0 ohm
(jumper wire)
Connect 277.0 ohm