AMI Analyzer Manual
Communications
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35
The “Solenoid Valve Pulse Time” should be set to zero if you don’t want to use the pulse feature. If you do,
set this to a suitable number in seconds – 15 seconds is normally OK – to drive a latching solenoid valve.
When going into alarm, alarm relay 1 will pulse closed (or open) for six seconds, and when coming out of
alarm, alarm relay 2 will pulse for six seconds. This is true no matter whether it is alarm 1 or alarm 2 that
goes into alarm: but both alarm 1 and alarm 2 have to be out of alarm for the alarm relay 2 to pulse.
If set to “Latching:, the alarms will stay triggered until someone presses the ALARM HOLD OFF button on the
analyzer. If set to “non-latching”, they will reset themselves when the oxygen level has gone back to the
non-alarm state, above or below set point (and hysteresis) as appropriate.
Alarm failsafe will cause the analyzer to attempt to set the alarms to the alarm state when it detects a power
failure, or when the power supply voltage it measures drops below 8.5 Volts. If the unit is DC powered from
a battery and solar panel combination, this setting will cause the analyzer to go into alarm when the battery
dies. On the other hand, if the unit is AC powered, or the DC power fails instantly, it probably will not have a
chance to fire the relays (since they need power to operate!)
Sensor Calibration Data:
This section shows information about the sensor. The Oxygen reading is repeated, and can be changed by
adjusting the span factor, just as if the unit is calibrated via the front panel.
The sensor information is read only – although you can submit a sensor serial number at the bottom of this
section when you insert a new sensor.
When you put in a new sensor, you can place the sensor in the analyzer and flow gas over it while you read
its serial number. Click on the NEW button, and make sure the box marked reset sensor is checked
(otherwise you will just change the serial number, but not tell the analyzer that the sensor is new). The
analyzer will record the date, and start timing various things about the new sensor, and it will copy these
timings over to the previous sensor fields so that you can see how the last one did.
The analyzer records the total time that the sensor has been installed (actually, since you told it that there
was a new sensor), the length of time that this sensor has seen temperatures over 110
º
F or below 32°F, the
number of hours that the analyzer has been unpowered, and the ppm hours (in units of 100,000 ppm hours).
If the sensor is only exposed to low ppm levels, this number may stay at zero for a very long time! The
reason for recording the length of time the analyzer was unpowered is that of course it can’t tell how much
oxygen the sensor was exposed to during that time.
This section also shows the data from the last sensor prior to the most recent one, so you can compare how
well they are doing.
This section also shows the calibration history of the analyzer. It records the date, the span factor when the
calibration is finished, and the oxygen reading at that time, which was presumably the oxygen level of the
span gas used. If you perform another calibration on the same day, it will overwrite the one you just did, but
