Analytical Industries GPR-3100 Series Oxygen Purity Analyzer - Manual (Page 19)

Advanced Instruments Inc.
5 Operation
GPR-3100 Rev 2/05 12
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.
Weak Sensor Indicator
A 5V output with negative ground is provided when the sensor is operational. The output is 0V when the
sensor output drops 20-25% from a baseline established at a previous calibration.
4-20mA and 0-1V Signal Outputs
The analyzer provides 0-1V full scale with negative ground and a 4-20mA full scale fully isolated ground
signals for external recording devices. The integral IC on the main PCB converts the 0-1V signal with
negative ground to a 4-20mA fully isolated signal. 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.
Caution:
The integral 4-20mA converter is internally powered and does not require external power. DO
NOT supply any voltage to either of the two terminals of the 4-20mA converter.
Range ID (identification)
A voltage output corresponding to each range is provided. The output of the highest range (normally
CAL) is 5V and the remaining three ranges 4V, 3V and 2V for the low range.
RS-232 / USB Port
The digital signal output is a standard 9-pin D connection type RS-232 serial communications port used
to connect the analyzer to a computer, terminal or other digital device.
Bi-directionsl data lines are provided via a RS-232C serial port for diagnostics and access via remote
computer that enables the user to obtain status information and initiate functions remotely.