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Calibration checks, Mv reading check, Rtd ohms reading check – Red Lion TLA User Manual

Page 11: Error flag e-cl, Alarm reset sequence alarm standby delay sequence, Thermocouple cold junction temperature check

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11

Alarm Reset Sequence

Alarm Standby Delay Sequence

ON

OFF

ALARM VALUE

OFF

ON

OFF

OFF

TIME

AUTOMATIC

RESET

MANUAL

RESET

MANUAL RESET

PERFORMED BY OPERATOR

INPUT

ALARM MODE

(ABSOLUTE LOW ACTING SHOWN)

ON

OFF

ON

OFF

ON

OFF

ON

ON

OFF

ON

OFF

ON

UNIT

POWER-ON

STANDBY

ENABLED

STANDBY
DISABLED

TIME

INPUT

ALARM VALUE

ALARM MODE

(ABSOLUTE LOW ACTING

W/AUTO-RESET SHOWN)

CALIBRATION CHECKS

The instrument has been fully calibrated at the factory for all input types. If

the unit appears to be indicating or controlling incorrectly, see the Troubleshooting

section before attempting this procedure.

If the TLA is suspected of reading incorrectly, the instrument may be checked

for indication accuracy without disturbing the factory calibration. The following

procedures may be used for this purpose.

Note: Allow ½ hour warm-up before checking these parameters.

mV Reading Check

1. Connect a DC mV source with an accuracy of 0.03% or better to terminal #8

(-) & #9 (+).

2. Configure Input Parameters Module 1 for linear mV (Lin) input, under tYPE.

3. Compare the TLA read-out to the standard at various points over the range

(-5.00 mV to 56.00 mV). The tolerance is ±(0.15% of reading + 1 LSD).

4. Calibrate the TLA if the readings are out of tolerance.

Thermocouple Cold Junction Temperature Check

1. Connect a thermocouple probe of known accuracy (Types T, E, J, K, N only)

to TLA. Select the probe used in Configure Module 1.

2. Connect a reference temperature probe to measuring end of thermocouple to

monitor temperature. Allow sufficient time for temperatures to equalize.

3. Compare TLA display with reference temperature probe. The TLA display

should equal the calibrated probe temperature. (Tolerance is ±1ºC.)

4. Calibrate the cold junction temperature if out of tolerance.

RTD Ohms Reading Check

1. Connect RTD simulator (with an accuracy of 0.1 ohm or better) capable of

operating with less than 150 µA to terminals #8, #9, & #10.

2. Configure Input Parameters Module 1 for linear ohms (rLin) input, under tYPE.

3. Compare the TLA read-out with the RTD simulator at various points over the

range 2.0 to 300.0 ohms. The tolerance is ±(0.3% of span + 1 LSD).

4. Calibrate the TLA RTD ohms if out of tolerance.

Error Flag E-CL

If error flag “E-CL” appears at power-up, a loss of calibration parameters due

to noise spikes has occurred. Entering code 77 twice in Factory Service

Operations Module (9-FS) erases the TLA calibration values and defaults the

values to nominal settings. Reading errors of ±10% may result. It is recommended

that the TLA be fully recalibrated. If using thermocouple only, the RTD

calibration need not be performed.

Note: the “E-CL” flag may be cleared by “stepping” through cold junction

calibration procedure without the need to change any calibration values. A

±10% reading error will still exist.

INPUT

DEVIATION LOW-ACTING WITH POSITIVE ALARM VALUE (d-LO)

SP + AL

OUTPUT OFF

LED ON

OUTPUT ON

LED OFF

SP

HYS

OUTPUT ON

LED OFF

OUTPUT OFF

LED ON

SP + (-AL)

DEVIATION LOW-ACTING WITH NEGATIVE ALARM VALUE (d-LO)

INPUT

LED ON

OUTPUT ON

LED OFF

OUTPUT OFF

LED ON

OUTPUT ON

LED OFF

OUTPUT OFF

SP

HYS

OUTPUT ON

LED OFF

OUTPUT OFF

LED ON

OUTPUT ON

LED OFF

INPUT

BAND INSIDE ACTING (b-IN)

SP + AL

OUTPUT OFF

LED ON

OUTPUT ON

LED OFF

OUTPUT OFF

LED ON

SP - AL

SP

HYS

HYS

SP - AL

LED ON

OUTPUT ON

LED OFF

OUTPUT OFF

LED ON

OUTPUT ON

SP + AL

BAND OUTSIDE ACTING (b-Ot)

INPUT

LED OFF

OUTPUT OFF

LED ON

OUTPUT ON

LED OFF

OUTPUT OFF

HYS

HYS

SP