VersaPro Temperature Controller
Page 45
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16.1 Calibration Displays and Keyboard Operation
When entering the Calibration Menu, the operator has to answer one of two questions depending on which I/O
functions have to be calibrated. If the CALIBRATION IN prompt is answered with a YES, then the parameters
related to the thermocouple input, millivolt input, and cold junction can be changed. If this prompt is skipped by
pressing the Enter key, then a second prompt, CALIBRATION OUT is displayed. If this prompt is answered
with a YES, then the zero and span values for both analog outputs can be changed.
In the Calibration Menu the displays and front panel keys take on special assignments. The LCD display
shows the input and calibration point being calibrated. The upper LED display indicates that the instrument is
in CAL mode. The lower LED display indicates the actual input level for the input channels or the calibration
factor for the output channels.
It is very important that the display is indicating the proper I/O parameter before making an adjustment or the
wrong value will be changed.
For the CAL INPUT calibration mode, the following keys perform the described functions:
Key
Function
UP ARROW
Increases the displayed value.
DOWN ARROW
Decreases the displayed value.
RIGHT ARROW
Shifts the flashing digit to the right and decreases the amount of adjustment or sensitivity
of the adjustment.
LEFT ARROW
Shifts the flashing digit to the left and increases the amount of adjustment or sensitivity
of the adjustment.
ENTER
Advances to next input value and saves the calibration changes.
SETUP
Exits the calibration mode.
16.2 Preparing for Input Calibration
The following is required to calibrate thermocouple and millivolt inputs:
Calibrated millivolt source, 0 – 2000mV with a 0.1 mV resolution
Calibrated microvolt source, -10mV to 50mV with a 0.1 uV resolution.
Copper wire to connect the millivolt source to the instrument.
Calibrated thermocouple simulator with internal cold junction compensation
Thermocouple extension wire for the type of thermocouple to be used.
In the Input Setup menu, select the thermocouple type to be used in the process. Enable Cold Junction
Compensation.
The first part of the calibration is in linear mode first. The thermocouple setting has no effect on the millivolt
readings in the first part of the input calibration but will effect the reading during the cold junction adjustment.