Myron L 729II - Manual (Page 34)

19. Continue or reinstall the front panel and tightly secure
retaining screws, see REASSEMBLY, page 31.
CAUTION: The sensor input and 0-5VDC output connectors
require only a small screwdriver or a pen to push on the release
levers. The release levers may be broken or damaged if not
pushed straight toward the CB. DO NOT push the release levers
sideways.
c. System Calibration
By following these steps the complete temperature system,
module and sensor, may be calibrated to better than ±0.2°
centigrade accuracy. This procedure is similar to the electronic
calibration except the sensor is attached and is allowed to
equilibrate in “ICE” water before adjusting the ZERO calibration
control.
NOTE: One of the above electronic calibration procedures, TPC
Module or precision resistors, must be performed BEFORE the
system calibration is performed. This is required to preset the
span between zero and full scale.
1. Ice must be crushed in water to form a very thick slurry.
A slurry is that condition where the water to ice ratio is
such that only sufficient water is present to allow easy
stirring. At this point, the temperature of the water will
be 0.000°C.
2. Immerse sensor and cable approximately 2” (50mm) into
slurry.
3. Allow to equilibrate. Slurry must be constantly stirred.
4. Continue stirring until no further change in temperature is
observed on the display.
5. Adjust TP Module ZERO calibration control to 000.0.
6. Continue or reinstall the front panel and tightly secure
retaining screws, see REASSEMBLY, page 31.
4. ALARM/CONTROL FUNCTION
You have now completed the installation and set up of your
Myron L Temperature Module option. Continue to set up and
adjust the control feature of the Temperature Module option
(-TH/THO & -SC/SCO), if installed.
The following assumes the TH/THO option has been installed at
the same time as the Temperature Module.
a. Set Point Conversion (SPC) /
Reversing Set Point
As shipped from the Myron L Company your Temperature
controller is configured to ALARM/control when the temperature is
to TOO HIGH. As many uses require the temperature to be
controlled by the use of a heater or chiller, the TPO Module may
be configured to maintain an elevated or lowered temperature as
required. If the configuration is correct for your requirements skip
to Temperature Set Point Adjust.
To reverse the set point ALARM/control operation:
1. Ensure power is OFF.
2. Locate the SPC on TP/TPO circuit board. See figures
III.C.1 & III.C.11.
3. Make a note of the current orientation of the SPC
jumpers.
4. Remove both jumpers. This is easily done by hand. Take
care not to crush the jumpers if using pliers.
5. Rotate the jumpers 1/4 turn (90°) and reinstall them on
their posts as shown in figure III.C.12.
6. Continue with Set Point adjustment.
30
Figure III.C.8
DV
-
+ 0.0
JUMPER
BR BL OR - +
Connect DVM leads as shown.
1000.0Ω RESISTOR
Figure III.C.9
DV
-
+ 5.0
JUMPER
BR BL OR - +
Connect DVM leads as shown.
1758.56Ω RESISTOR
Figure III.C.10
199.9
FRONT PANEL DISPLAY
Figure III.C.11
FS
INC
INC
TEMP
CONTROL
HARNESS
DETAIL OF SET POINT CONVERSION (SPC)
ON TP/TPO MODULE AS CONFIGURED
WHEN SHIPPED FROM THE MFR.
SET POINT
CONVERSION (SPC)
DEC DEC
SPC