PortaSens
III
Portable Gas Leak Detector, Model D16
Operation and Maintenance Manual
Rev-A Feb 2018
- 31 -
Pump
The D16 pump draws gas to the sensor through the inlet port. The
pump is connected to a DC motor whose speed is controlled by the “duty
cycle” of a PWM (pulse-width-modulated) signal. The duty cycle is
proportional to the motor speed and is preset at the factory for a flowrate of
400cc/min (0.85 SCFH), and can be adjusted.
The pump motor momentarily runs fast when it starts. This speeds up
delivery of gas to the sensor, and helps to insure the motor starts when cold.
A blockage of the inlet or outlet port also causes the pump motor to speed
up. The pump will not usually be damaged by operating with a blockage for
a short time, but doing so will increase the transport time of gas to the
sensor, and will also decrease the battery life.
A flow meter is included in the accessory
kit to verify the flow rate. To
use it, connect the sampling wand and push the flow meter’s tubing adapter
onto the tip. Hold the D16 so the meter is vertical, and verify the flow rate is
250 – 400 cc/min. If required, adjust the “Duty Cycle” setting in the “Pump”
configuration menu (below).
Proper flow should be verified before use.
Pump Status
When a blockage occurs, the D16 beeps once and displays, "
CHECK
FLOW
", in upper right corner of the Main Display. See Pump Troubles on
page 58 for further details about corrective actions for pump problems.
Figure 18 Pump status on “Main Display”.
The pump stops running when the sensor is removed, and when the
trouble alarm is active (“Trouble” page is visible). The pump motor may be
disabled for diffusion mode sampling. When this occurs, “
PUMP OFF
”
appears in the upper right corner of the “Main Display”.