AMI Analyzer Manual
Expanded Installation Procedure
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16
c.
Verify the output calibration.
You should only need to do this if your flow computer or similar monitoring device has an uncalibrated
input.
i.
Connect the analog output terminals to an appropriate measuring device – preferably
the flow computer or similar monitoring device you are going to be using with this
analyzer.
You can simply use a multi meter connected to the output terminals. If so, make sure it is set correctly –
don’t use a voltmeter to measure current! Often people leave their meter in the current measurement
position and the next time they measure a voltage they blow the current fuse. If this has happened, the
meter won’t measure current until you replace it.
ii.
Arrange that you can readily see the reading given by this device.
iii.
On the AMI User Interface, check the “Zero” check box under SETUP in the ANALYZER
SETUP section.
iv.
Observe the response of the monitoring device, and adjust the number in the box next
to the Zero label until the monitoring device shows what it considers to be zero (which
should correspond with 4mA).
v.
Check the box marked “Full Scale” in the SETUP section, and adjust the number in the
box next to it until the monitoring device shows full scale. This corresponds to 20mA.
vi.
Check the “Mid Range” box and verify that the monitoring device shows mid scale.
vii.
Uncheck any checked box (if you forget, the analyzer will revert to its ordinary operation
in ten minutes anyway).
12. Test the entire system, including anything controlled by the alarms or analog output, using a cell
simulator.
As an option, AMI can provide a “Cell Simulator” that mimics the operation of a sensor between 0-100ppm,
so that you can verify that your control system or flow computer correctly reads the analyzer’s output and
responds correctly to the alarm contacts.
13. Turn off the sample flow by closing the needle valve all the way
You don’t want to dilute the air under the sensor when you first place it in the analyzer. Don’t tighten the
needle valve or you will damage it – just turn it down until it stops.
14. 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.
Bear in mind that if you have returned the sample to the source, you will be flowing air into the source while
you do this. You may want to temporarily exhaust the sample to room air, and connect it to the source
when you are done with this procedure.
