AMI Analyzer Manual
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4
The AMI Oxygen Probe Analyzer
Introduction
The Advanced Micro Instruments Oxygen Probe is designed for monitoring of oxygen content in a nitrogen
or similar inert gas stream. It operates on a single range, normally 0-25% oxygen, and produces an output
typically 0-2.5V DC over this range. It uses
12
-2
4
V DC power, and it provides a regulated 5VDC output as
an auxiliary for low power devices such as LCD panel meters. No calibration is provided internally:
calibration is performed either by the host system to which it is attached or else by the optional meter
display unit.
Features:
•
Compact size
•
Single range operation
•
Probe may be mounted up to 100ft from a suitable display unit.
•
Air calibration, no zero or span gases required
•
Virtually unaffected by hydrocarbons or other oxidizable gases
•
High accuracy and fast response
•
Backed by a two year warranty
Options:
•
Meter display unit with analog voltage output from 4-20 mA
Oxygen sensor:
AMI uses an industry standard electrochemical sensor. This measures the concentration of oxygen in a gas
stream, using an oxygen specific chemistry. It generates an output current in proportion to the amount of
oxygen present, and has zero output in the absence of oxygen, thus avoiding any requirement to zero the
analyzer. The cell is linear throughout its range. The span calibration may be performed using standard
span gases or ambient air.
Percent level analyzers are routinely calibrated on air. Air has a reliable 20.94% oxygen
in it
at 50%
relative humidity at 0
°C (32°F)
, when dry. In the case of its use as an area monitor it is advisable to use a
known high quality air supply for calibration since the room air may not contain 20.94% of oxygen!