Chandler Engineering AMETEK 7200, Instruction Manual

Page: 45 / 77

SECTION 4 – CALIBRATION 4 - 5
Perform this calibration at several temperatures, spanning the entire range of the CHA (20°C
to 163°C).
Draw a straight line through the data (or otherwise calculate a linear curve fit through the
data to obtain a
Slope value of known °C / Uncalibrated Value °C to be entered in the
Slope control.
Likewise, from this same curve fit, obtain the Intercept value to be entered in the Intercept
control.
Click
Cancel to abort and not use any recalibration you have performed or click OK to save
the calibration parameters and use them to measure temperature.
Temperature Calibration (Oven)
The two thermocouples used by the Model 7200 CHA to measure Oven Temperature (and
independently measure the same for the Hi-Limit controller) are standard type J
thermocouples which provide a changing voltage output relative to the temperature.
The CHA-Control software reads the
Oven Temperature from the Oven Temperature
controller. The CHA-Control software uses the Oven Temperature , as read from and
displayed by the controller with no further conversion or correction.
The CHA-Control software does not read, display, or use the Hi-Limit Temperature.
These temperatures are calibrated by Chandler Engineering. If you wish to perform a re-
calibration of the Oven Temperature, use Step 5 of the procedure #7200-1060 to calibrate it
to match the Cement Temperature sensor (RTD), after first calibrating the Cement
Temperature according to the previous section.
If you wish to calibrate the Hi-Limit Temperature, Chandler Engineering recommends that
you first place the thermocouple in a traceable temperature standard calibrator.
Use the calibrator block to heat or cool the thermocouple to a known, actual traceable
temperature, and make a note of the actual known calibrator temperature vs.
“actual”
temperature as displayed on the Hi-Limit temperature controller front panel.
Perform this calibration at several temperatures, spanning the entire range of the CHA
instrument’s range (appro x. ambient temperature 20°C to 163°C).
Draw a straight line through the data (or otherwise calculate a linear curve fit through the
data. If the temperature as read by the controller is outside your acceptable limits of
accuracy, you can simply enter a necessary offset correction val
ue as the “SHif” (“PV Shift”)
parameter in the Hi-Limit temperature controller (See the manufacturer ’s instruction manual
for the controller, for details of how to access, enter, and save this value).
Please note that in the oven instruction manual, you should ignore most of the details for how
to set its Oven Temperature controller because the controller was replaced at Chandler
Engineering.
See procedure #7200-1060, and the controller manual, on how to properly set up the
controller.