Section 6
Page 6 - 6
MODEL 346 INSTALLATION AND OPERATION MANUAL
HA243821
Issue 5 Mar 98
6.3.1 CALIBRATION PAGES (Cont.)
CHANNEL RANGES
This calibration procedure allows the selection of a specific hardware range for the recorder to use. Refer to
section 1.3 for details of the available hardware ranges.
Change Cal?
Input Channel
Operation of the ENTER key allows a channel number to be chosen, using the up/down arrows, followed by
ENTER.
Choose Range
20mV
Operation of the up/down arrow keys allows the hardware range to be selected from the list below. Because
the recorder internal operating span (gain) is chosen automatically when range low and high are entered (sec-
tion 4.8), it is recommended that all ranges are calibrated.20mV, 60mV (this range must be calibrated before
the CJC is calibrated), 80mV, 200mV, 400mV, 1.7V (this range must be calibrated before the CJC), 2.5V,
5.0V, Ohms (RTD current defined.)
Note...
Precision input sources must be connected and set to the proper value before this calibration procedure is
continued.
C1 Apply High
20.00 mV
The input source should be set to the displayed value (20mV in this example). Operation of the page scroll key
enters the new calibration, after a short delay accompanied by a ‘Wait’ message at the display. The process is
repeated for the apply low display. Should it not be practical to attain exactly the suggested input value, the
up/down /side arrow keys are used to enter that value which is attainable.
Once the adjustments are complete, the CLEAR key is operated twice to return to the ‘Change Cal ?’ display.
CJ SENSOR
This part of the calibration procedure requires the connection of a type J thermocouple, at a known tempera-
ture, or of a Type J thermocouple simulator.
Change Cal?
C J Sensor
Operation of the ENTER key allows the selection of input board 1 or 2 for calibration, by means of the up/down
arrow keys, followed by ENTER.
Enter Ref. Temp.
XX.X ˚C
The up/down/side arrows are used to enter the type J or simulator Input temperature.
An alternative method is to short-out the input of channel 1, measure the temperature between channel 1 and 2
input terminals (as closely as possible to the CJ sensor), and to enter this value as a reference temperature.