Alibrating, Eter – Red Lion PAXLTC User Manual
Page 7
The meter has been fully calibrated at the factory. If the meter appears to be
indicating incorrectly or inaccurately, refer to the troubleshooting section before
attempting this procedure. When re-calibration is required (generally every 2
years), the procedure should only be performed by qualified technicians using
appropriate equipment. A precision thermometer (RTD, thermistor or similar
type with an accuracy of ±0.3° C) and an accurate voltage source (0.01%) are
required. The procedure consists of setting the cold junction temperature and
applying accurate voltages to the meter input in a series of three steps. Allow a
60-minute warm-up before starting calibration.
COLD JUNCTION TEMPERATURE CALIBRATION
1. Connect a calibrated thermocouple (types T, E, J, K or N only) to the panel
meter. Select the thermocouple type used in programming.
2. Connect the reference thermometer to the measuring end of the thermocouple.
The two probes should be shielded from air movement and allowed sufficient
time to equalize in temperature. (As an alternative, the PAXLTC thermocouple
probe may be placed in a calibration bath of known temperature.)
3. From the normal indicator display mode, compare the display temperature to
that of the reference thermometer. Allow 10 minutes for the temperature to
equalize. The meter and the reference thermometer should agree to within 1° F
(0.6° C).
4. If cold junction re-calibration is necessary (temperature out of tolerance), enter
meter calibration mode and enter access Code 48. The meter display will
alternate between
and the old cold junction reading. At this point, key-in
the new cold junction temperature according to the formula:
WHERE:
New Cold Junction Reading = Old Cold Junction Reading + Difference
(Difference = Reference Thermometer Temperature - Meter Display Temperature)
5. Press PAR. The meter briefly displays
to acknowledge the new cold
junction value.
VOLTAGE CALIBRATION
Following cold junction calibration, the display
< >
/
appears.
Enter if input voltage calibration is desired. If is entered, the meter exits
calibration and returns to normal display mode.
The meter briefly displays
and returns to the normal display mode.
Calibration is now complete.
It is recommended to check calibration by selecting mV indication mode for
thermocouple type (
< >
) and verifying unit accuracy at various
points over the range of the meter (-10 to +80 mV).
7
The factory settings for the programming parameters are shown in the
previous section in the alternating display illustrations. All programming
parameters can be restored to the factory default settings by entering the access
Code 66 and pressing the PAR key. The meter briefly displays
and then
returns to Code 50. This procedure resets only parameters that are accessed
through Programming Mode. The Calibration Mode settings (input calibration
levels) are not affected.
UNITS LABEL BACKLIGHT
to
PROGRAMMING MODE EXIT
FACTORY SETTINGS
CALIBRATION MODE
5.0 C
ALIBRATING
THE
M
ETER
DISPLAY
PARAMETERS
DESCRIPTION/COMMENT
0.000 mV
Apply 0.000 mV, wait 20 seconds, press PAR.
30.000 mV
Apply 30.000 mV, wait 20 seconds, press PAR.
60.000 mV
Apply 60.000 mV, wait 20 seconds, press PAR.
The Units Label Kit Accessory contains a sheet of custom unit overlays,
which can be installed in the meter bezel display assembly. The unit of measure
for the meter display is then visible when the label backlight is illuminated. The
two most commonly used temperature unit labels (°F and °C) are supplied with
the meter. Press the up or down arrow keys to select whether the units label
backlight is illuminated. Press the PAR key to save the selection and advance
to the next parameter.
Before exiting Programming Mode, the meter offers the choice of entering
Calibration Mode. To exit Programming Mode without entering Calibration
Mode, select
and press the PAR key. The meter briefly displays
and
returns to the normal display mode. All programmed selections are now
transferred to non-volatile memory and are retained if power is removed from
the meter.
(If power loss occurs during Programming Mode, verify parameter changes
and reprogram, if necessary, when power is restored.)
To enter Calibration Mode, select
< >
at the end of Programming
Mode, and press the PAR key. In Calibration Mode, the user can restore the
meter to factory default settings or recalibrate the signal input if necessary.
To prevent inadvertent entries, an access code must be entered to perform any
operation in Calibration Mode. Upon entering Calibration Mode, the meter
initially displays Code 50. Press the up or down arrow keys to select the access
code for the desired operation. If an access code other than those shown below
is entered, the meter exits Calibration Mode and returns to normal display mode.
METER INPUT CALIBRATION