Advanced Instruments Inc.
Note: When making connections the user must decide whether to configure/connect Alarm 1 and Alarm 2 in failsafe
mode (Normally Open – NO – where the alarm relay de-energizes and closes in an alarm condition) or non-failsafe
mode (Normally Closed – NC – where alarm relay energizes and opens in an alarm condition).
Power Failure Alarm
A dry contact rated at 30VDC @ 1A is provided as a power failure alarm that activates when power supplied to the
analyzer’s circuits is unacceptable. The contact is normally closed but opens when the power to the analyzer is
switched off or interrupted and cannot be disabled.
4-20mA Signal Output and Range ID
The analyzer provides a 4-20mA full scale fully isolated ground signals for external recording devices. The integral IC
on the main PCB provides 4-20mA fully isolated signals for output and range ID. The 4-20mA current output is
obtained by connecting the current measuring device between the positive and negative terminals labeled OUTPUT
4-20mA. To check the signal output of the 4-20mA E/I integrated circuit connect an ammeter as the measuring
device and confirm the output is 0.1mA of 4mA. A finer adjustment of the zero offset of the 4-20mA
converter can be provided by a potentiometer mounted on the main PCB Assembly. Consult factory for instructions
For range ID the output of 4mA, 8mA, 12mA, 16mA, 20mA correspond to the most sensitive to least sensitive
analysis range.
Caution:
The integral 4-20mA converters are internally powered and do not require external power. DO NOT supply
any voltage to any of the two terminals of the 4-20mA converter.
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