PortaSens II
Gas Detector
C16 Leak Detector
O & M Manual
Rev. G, 11/07
- 13 -
GAS CONCENTRATION ALARM FUNCTIONS
The
PortaSens II
Leak Detector contains both visual and audible gas concentration
alarm functions. Three alarm levels are provided, with adjustable set points (SP) for each alarm.
The alarms are designated as CAUTION, WARNING, and ALARM. The Caution setting is
normally adjusted to alarm if the installed gas sensor exhibits excessive negative zero drift. The
Warning and Alarm levels are set to specific gas values to provide an indication of high
concentrations. Note that the Caution, Warning, and Alarm functions are only active when the
C16 is operating in the normal mode. When in Calibrate or Sampling modes, the alarms are
disabled.
When the gas detector is in operation, the measured gas concentration is always being
compared to the alarm set points. When the concentration exceeds the Warning set-point for 2
seconds, the LCD display will flash the message "WARNING" and the audible beeper will sound
intermittently. If the Alarm set-point is exceeded, the display will flash the "ALARM" message and
the audible beeper will sound continuously. If excessive zero drift is detected, the Caution
message will flash, indicating that the sensor zero should be checked and adjusted if necessary.
The Caution alarm will not activate the internal horn. To silence the alarm horn and stop the
display flash, press the ACK key. Note that the alarm acknowledge key (ACK) will only appear
during an alarm condition. All alarm set points can be changed by the user or can be turned off if
desired. Refer to the instructions on page 21 for the proper adjustment procedures.
PUMP TROUBLE ALARM
An internal diaphragm pump continuously delivers an air sample to the flow manifold
containing the gas sensor. In normal operation, the flow rate is approx. 400 cc/min. Blockage in
either the inlet or outlet will increase the sample transport time to the analyzer, resulting in a
much slower response time. Should the pump fail during normal operation, the LCD display will
indicate the message "PUMP TROUBLE" and the internal audible horn will sound intermittently.
The internal pump will generally not be damaged by short term operation with the flow
blocked. It is possible for the pump motor to run, even when there is no air being pumped
through the system. This condition can occur if the pump is filled with water or if the filter
becomes completely blocked. A flowmeter is included in the
PortaSens II
kit to allow quick
verification of proper flow. Turn the instrument on and connect the sampling wand. Place the tip
of the sampling wand into the tubing adapter attached to the flowmeter. Hold the flowmeter in the
vertical position and verify that the flowrate is above 250 cc/min (
0.5 SCFH
).
Proper flow
should always be verified before using the PortaSens for leak testing.
