AMI Analyzer Manual
Expanded Installation Procedure
15
BOTH ENDS! If you do so, you will generate a ground loop which will seriously upset the readings. Normally
you would use the ground terminal for a shield. You can select which output is in use. The voltage output is
lower power, but more prone to interference. If you decide to change it, you will probably have to perform
an output calibration, described later in this manual.
The two terminals marked A and B are for the RS-485 ModBus connection. This is not isolated from ground.
Run the power through one conduit, and the analog output and RS485 lines through the other.
Make sure you are following the NEC (National Electrical Code) when you wire it up. Also make sure you
have a way of removing power from the analyzer nearby, per the code.
13.
Power up analyzer.
When you do so, the LCD should light up.
14. Turn the Sample/Span/Off valve to OFF.
15. Unscrew the cell cap, and install the oxygen sensor.
Unscrew the cap first. Open the sensor bag, remove the sensor by holding the little handle and
immediately put it into the cell compartment, gold side up, and with the little metal tag on the side facing
you. When it is in place, hold the sensor in place and pull out the tag. Do it in this order so that the sensor
is always operating, eating up oxygen that gets in through its membrane. The length of time you take over
this is critical in determining how long the sensor takes to get down to a low range.
16. Optional: in the User Interface (version III) press the “NEW SENSOR” button, and record the
sensor serial number.
You might just want to write it down. Note that you can read the serial number while the sensor is in place
in its cell block pocket – don’t leave the sensor out while you write it down.
17. Stabilize for 45 seconds ONLY, adjust span to 20.9%.
It will take the sensor about 20 seconds to come to a reasonably stable reading, but give it 45 seconds to be
sure. Don’t go over this time, even if the reading is still moving. The sensor is probably changing
temperature a bit which affects its reading until it has equilibrated with the analyzer. You aren’t concerned
with the utmost precision at this point, just a close-enough value. If you leave the sensor in air too long, it
will take much longer to come down to low oxygen levels than you expect.
18. IMMEDIATELY turn the Sample/Span/Off valve to SAMPLE.
Do this before you screw on the cell cap, because you will get rid of most of the air in the cell pocket
immediately, helping the sensor come down quickly.
19.
Purge with sample gas for half an hour, or until the oxygen reading has fallen to low ppm levels
