ENMET OMNI-4000 - Manual (Page 21)

OMNI-4000 S/N 6705 and above ENMET Corporation
15
2.0 Operation
2.1 Using the OMNI-4000
This Chapter deals with the positioning of the OMNI-4000 for taking readings and the use of the remote sampling
system.
2.1.1 Positioning the Instrument
The operator can:
• Work while the OMNI-4000 monitors the atmosphere
• Or, take readings using a sampling system
In order to monitor the atmosphere correctly, the openings for the sensors of the OMNI-4000 must always be
unrestricted. A blocked sensor opening results in a reduced evaluation of the gas concentration, which may prove fatal
for the operator.
Carrying the OMNI-4000 with a Shoulder Strap
A shoulder strap allows the OMNI-4000 to be carried by the operator. See Figure 2-1. The device is designed so that
the sensors are facing away from the clothing. Thus, the gas exchange openings can be seen, and are unrestricted in
use, and the display can be clearly seen.
2.1.2 Use With a Sampling Probe
The OMNI-4000 can be connected to a sampling system, enabling readings to be taken in inaccessible areas or prior to
entering a confined space.
Setting-Up the Sampling System
• Position the calibration cover on the OMNI-4000 body. See Figure 2-2. Fasten it in place with the captive screw.
• Connect the vinyl hose between the cover nipple and the inlet to the squeeze pump or to the motorized sampling
pump.
• Ensure that pumping direction is correct by checking the flow of air into the sensors during pumping.
Pumping and Readings
• When using the squeeze bulb, squeeze the bulb rapidly and continuously for 2 seconds for each foot of hose
before looking at the reading.
• Wait until the readings have stabilized before confirming them. They may be over estimated (explosive gases) or
under estimated (oxygen) during pumping as a result of the movement of air.
Dismantling the Pumping System
• Always remove the calibration cover after using the probe. Failure to do so may lead to an underestimation in
the readings which may be fatal for the operator.
2.1.3 Use with an Integral Sampling Pump
The instrument may be purchased with an integral sampling pump, the BP-4000, or such a pump may be added in the
field. The pump replaces the instrument battery pack, and includes a battery pack of larger capacity, sufficient to power
both the instrument and the pump. The integral pump adds about 2 inches to the length of the instrument. Note that the
instrument battery pack and the integral pump battery pack require two different chargers. See battery life table 4-2 in
section 4.