1 introduction, 2 zero calibration – Monarch Instrument DC 2000 User Manual
Page 119
Chapter 6 Calibration
Page 6-1
6.1 Introduction
This chapter includes the procedures to calibrate the Analog-to-Digital Converter (ADC) circuit board and the RTD
current source. The actual calibration constants are automatically stored in Flash Memory on the analog to digital
converter boards.
WARNING:
Do not attempt to perform calibration unless you are fully prepared to do so. Incorrect
procedures can destroy factory calibration. Read this entire chapter before attempting to
calibrate the unit.
NOTE: Allow the Recorder to warm up and stabilize before attempting calibration. 15 minutes warm up time at
room temperature is recommended.
6.1.1 Routine Calibration
Routine calibration should be performed to maintain the accuracy of the instrument. The following items must
be performed for a routine calibration:
•
Zero Calibrate all channels
•
Calibrate the ADC Scales
•
RTD Current
6.1.2 Calibration Equipment
The following equipment items are necessary to calibrate the instrument:
•
One precision voltage source (accurate to ± 5 microvolts) adjustable from 10 microvolts to 25 Volts
•
One precision resistor 250 ohms 0.05% - Required for calibrating RTD
6.2 Zero Calibration
Before the scales or RTD current are calibrated, a zero calibration must be done. A zero calibration must be done
when new channels are installed into the ADC board.
Insert a jumper onto all channels (see the Unused Input diagram in Figure 2.7). From the Hidden menu use the UP
(
↑
) or DOWN (
↓
) Arrow Keys to select “ADC Control” and press ENTER. Use the UP (
↑
) or DOWN (
↓
) Arrow Keys
to select “Cal ADC” and press ENTER. Use the UP (
↑
) or DOWN (
↓
) Arrow Keys to select “Cal scales” and press
ENTER. Use the UP (
↑
) or DOWN (
↓
) Arrow Keys to select “Zero cal.” and press ENTER.
NOTE: Zero calibration must be done to all channels. The dialog box will only show the readings from channel 1.
Once the Zero calibration is done, remove the jumpers and press EXIT three times to get back to the Hidden menu.