Detcon PI-600 - Manual (Page 32)

calibration fault screen which appears as “SPAN FAULT #2”. Previous span calibration is retained.
Memory Fault
If new data points cannot successfully be stored to memory the display will indicate: “MEMORY FAULT”.
Fail-Safe/Fault Supervision
Detcon MicroSafe™ sensors are programmed for fail-safe operation. All fault conditions will illuminate the fault LED,
and cause the display to read its corresponding fault condition: “ZERO FAULT”, “SENSOR FAULT”, “SPAN
FAULT #1”, or “SPAN FAULT #2”. A “SENSOR FAULT” and “ZERO FAULT” will cause the mA output to
drop to zero (0) mA.
Sensor Life
The “Sensor Life” feature gauges the remaining sensor life based on signal output from the PID sensor cell. When a sen-
sor life of 25% or less remains, the sensor cell should be replaced within a reasonable maintenance schedule.
3.12 D ISPLAY C ONTRAST A DJUST
Detcon MicroSafe™ sensors feature a 16 character backlit liquid crystal display. Like most LCDs, character contrast can
be affected by viewing angle and temperature. Temperature compensation circuitry included in the MicroSafe™ design
will compensate for this characteristic, however temperature extremes may still cause a shift in the contrast. Display con-
trast can be adjusted by the user if necessary. However, changing the contrast requires that the sensor housing be
opened, thus declassif ication of the area is required.
To adjust the display contrast, remove the enclosure cover and use a jewelers screwdriver to turn the contrast adjust screw
located beneath the metallic face plate. The adjustment location is marked “CONTRAST”. See f igure 6 for location.
3.13 U NIVERSAL T RANSMITTER F EATURE (R E -I NITIALIZATION )
The Model PI-600 uses a universal transmitter design that allows the transmitter to be set up for any target gas and any
toxic concentration range. The original transmitter set-up is done at Detcon Inc. as part of the sensor test and calibra-
tion procedure, but it may also be changed in the f ield if necessary. The Universal Transmitter feature is a signif icant
convenience to the user because it allows hardware f lexibility and minimizes the spare parts requirements to handle
unexpected transmitter failures of different gas/ranges. It is however, absolutely critical that changes to gas/range set-up
of the Universal Transmitter be consistent with the gas type and range of the PID Sensor Head that it is connected to.
The PID sensor head will display the range it is set up for, based on the isobutylene reference calibration.
NOTE: If the Universal Transmitter is changed for gas type and range, it must be consistent with the PID sensor head
it is mated with.
If the Universal Transmitter needs to be changed for gas type and range follow this procedure. First, unplug the trans-
mitter temporarily and then plug it back in. While the message “Universal Transmitter” appears, take the program mag-
net and swipe it over magnet PGM1. This will reveal the set-up options for gas range and gas type.
Swipe over PGM1to advance through the options for gas range which include:
1, 2, 3….10 ppm
10, 15, 20……100 ppm
100, 200, 300…..1000 ppm
1000, 2000, 3000 …..10,000 ppm
When the correct range is displayed, hold magnet over PGM1 for 3 seconds to accept the selection.
Next is your selection for the gas type that will be displayed. Note, the default gas is “VOC”. In this set-up you will
enter the alpha-numeric characters of the gas type. There is space for the chemical formula name of up to six characters.
Use PGM1 and PGM2 swipes to advance through the alphabet and numbers 0-9 selection (there is a blank space after
9). When the correct alphanumeric character is highlighted, hold the magnet over PGM1 for 3 seconds to lock it in.
This moves you to the next blank and the procedure is repeated until the chemical formula is completed. After the 6th
character is locked in the transmitter will proceed to normal operation.
PI-600 Toxic Gas Sensors PG.32