AMI Analyzer Manual
Installation Procedure
18
Make sure you don’t cross thread it, and make sure it is tightened down firmly but not so much you will
need a tool to undo it. There is no need to panic about getting it on fast, since the flow of sample gas will
purge the sensor while you are working on it.
24. Seal the electrical seals.
It is essential that you do this! Follow the instructions that come with the seal-offs.
25. Screw on the cap on the explosion-proof (left side) section of the analyzer.
Again, this is essential.
26. If desired, span with known calibration gas.
a) Connect a regulator to the span gas tank.
b) Shut off the regulator outlet valve and leak check all fittings, gauges and packing glands with
Snoop
or equivalent.
Again, flow the liquid on, don’t spray it on. Make sure you check the regulator and tank valve as well.
c) Flow calibration gas preferably through a length of AMI supplied tubing WHILE you are
connecting the tubing to the span gas fitting. Allow the gas to purge around the fitting for
about 20 seconds before you tighten it.
It is preferable to use the AMI special flexible non-diffusive tubing with its O-ring sealed fittings so that you
don’t destroy the span inlet fitting on the analyzer. This can be purchased from AMI as an option.
Compression fittings can only take a few openings and closings before they cease to seal well enough for a
trace oxygen analyzer. Flow the gas through the tubing while you attach it to the span fitting: screw it on by
one thread allowing the gas to escape around it, and after about 20 seconds tighten it up. This displaces the
air from the fitting, meaning that you don’t inject a slug of air onto the sensor and delay it coming to
stability.
d) Tighten fitting on the span gas inlet.
Use Snoop™ or equivalent to leak check it.
e) Press the ALARM HOLD OFF button, and adjust the time displayed to a suitable value (typically
10 minutes).
Do this so you won’t fire the alarms possibly causing all kinds of unnecessary havoc in your control system.
Note that doing this will also hold the analog output at its last value.
f)
Turn the analyzer Sample/Span/Off valve to the SPAN position.
You will probably see the reading shoot up for a moment as the air in the span gas port is pushed past the
sensor, then the reading will start to stabilize.
g) Allow to stabilize for 2 minutes.
This will allow any residual air to be flushed out and the sensor to come to equilibrium.
h) Verify that the analyzer reads within about 15% of the span gas value.