External Water-Trap Filter; Alarms; Alarm Signals; Alarm Signal Summary - WatchGas NEO User Manual

NEO
Photo-ionization Detector

3.6 EXTERNAL WATER-TRAP FILTER

The external filter is made of a PTFE (Teflon ®) or PVDF membrane with 0.45 micron pore
size to prevent dust or other particles from being sucked into the sensor manifold, which
could damage the instrument. It prolongs the operating life of the sensor and pump. To
install the external filter, simply screw it in to the instrument's inlet probe using the Luer
connection.

4. ALARMS

4.1 ALARM SIGNALS

During each measurement period, the gas concentration is compared with the programmed
alarm limits (gas concentration alarm limit settings). If the concentration exceeds any of
the preset limits, the buzzer and red flashing LED are activated immediately to warn of
the alarm condition.
In addition, the instrument alarms under various other fault conditions, including low
battery voltage, UV lamp failure, pump stall gas concentration over-range, etc, as shown
below.

4.2 ALARM SIGNAL SUMMARY

MESSAGE CONDITION
HIGH Gas exceeds 'High Alarm' limit
OVR Gas exceeds measurement range
MAX Gas exceeds electronics'
maximum range
LOW Gas exceeds 'Low Alarm' limit
TWA Gas exceeds 'TWA' limit
STEL Gas exceeds 'STEL' limit
Pump icon Pump failure
flashes
Lamp PID lamp failure
Battery icon Low battery
flashes
CAL Calibration failed, or is overdue
NEG Gas reading measures less than
number stored in calibration
4.3 PRESET ALARM LIMITS & CALIBRATION
The instrument is factory calibrated with standard calibration gas, and is programmed
with default alarm limits. For example, on the NEO PPM, the default values are:
CAL GAS CAL SPAN
Isobutylene
Alarm limits and calibration parameters can be adjusted in Configuration Mode as desired
for particular testing purposes and applications.
10
UNIT LOW
10 ppm 50
ALARM SIGNAL
3 beeps/flashes per second
3 beeps/flashes per second
3 beeps/flashes per second
2 beeps/flashes per second
1 Beep/flash per second
1 Beep/flash per second
3 beeps/flashes per second
3 beeps/flashes per second
plus 'Lamp' message
1 flash, 1 beep per minute
plus battery icon flashes
1 beep/flash per second
1 beep/flash per second
HIGH TWA STEL
100 10 25