16
2.
FURTHER SETUP PARAMETERS
Power on the Gas-Rover with the left “Power On” button and while the detector displays
“
Bascom-Turner Gas-Rover
”, press the right button once and the center button once. A menu of
four choices will be displayed:
Cal Due Time
Pump Current
New Filament
Power Off
The left “Yes” button selects the option indicated by the pointer and the right “No” button
advances the pointer to the next line.
Cal-Due Time.
The Gas-Rover should be calibrated regularly and this parameter specifies
the desired calibration period in days. When the detector is turned on, the Gas-Rover notifies the
operator when calibration is due. If the calibration period has expired, the Gas-Rover reminds the
operator that calibration is overdue by waiting at the Calibration Due screen. The “Override”
button allows the operator to continue and use the instrument. The factory setting for the
calibration period is 31 days; this parameter may be set from 1 to 91 days.
Pump Current.
The test starts with the pump off, indicated by 0, and a current that should
be a small number, less than 5, possibly negative. The left “Up” key turns the pump on. The
nominal current is 50 ma, range 40-60 ma. When the detector intake is blocked, the pump current
should increase significantly, nominally to 220 ma. Typically, the pump current rises by about 15
ma when a hose and probe are attached.
The Pump Noise test follows when the “Exit” key is pressed. Pump Noise is meaningful
only under load, i.e. when hose, probe, and filters are connected to the detector’s intake nozzle.
The detector should not be handled or moved when the pump noise test is running.
Pump Noise (Typical)
Off
On
3.5
7.4
The pump is cycled through Off and On, in round robin fashion, while the overall sensor
noise is measured. Because of thermal drift, this test must be run for about 3 minutes before
meaningful noise numbers are displayed.
The noise shown in the “Off” column is independent of the pump. When new, the methane
sensor noise should be less than 5.0. As the sensor ages, the noise may increase somewhat, but
should remain less than 8.0. The noise with the pump on should be less than 12.0. The noise
numbers change as the test runs and typical numbers should be used for interpretation; an
occasional high number is not significant and may be ignored.
New Sensor.
This screen
must
be run after a new sensor is installed and before the sensor
is first calibrated. To start the new sensor process, press the left “Run” button. After a “
Please
Ensure Clean Air
” screen, the instrument reverts to a normal start up screen and proceeds through
the various screens to a mandatory calibration screen, either one gas or two gas, the latter in the
sequence methane or system gas first and then followed by calibration with CAL gas.