Biosystems MultiPro Reference Manual - 3. Sampling
15
Bad
Invalid Memory Type
009
No Sensors Installed
010
Bad Temp Sensor
012
Bad Vibrating Alarm
014
If the MultiPro displays an error message,
contact Biosystems for further instructions.
3. Sampling
The MultiPro may
be used in either
diffusion or
sample-draw
mode. In either
mode, the gas
sample must reach
the sensors for the
instrument to
register a gas
reading. The
sensors are located at the bottom of the
instrument.
The sensor ports must
be kept free of obstruction. Blocked
sensor ports can lead to inaccurate and
potentially dangerous readings.
In diffusion mode, the atmosphere being
measured reaches the sensors by diffusing
through vents at the bottom of the
instrument. Normal air movements are
enough to carry the sample to the sensors.
The sensors react quickly to changes in the
concentrations of the gases being measured.
Diffusion-style operation monitors only the
atmosphere that immediately surrounds the
detector.
The MultiPro can also be used to sample
remote locations with either the hand-
aspirated sample-draw kit, or with the
motorized sample draw pump. During
remote sampling, the gas sample is drawn
into the sensor compartment through the
probe assembly and a length of tubing.
3.1
Manual sample draw kit
The manual sample draw kit is comprised of
a sample draw probe, 2 sections of tubing, a
squeeze bulb and an adapter that is used to
connect the sample draw accessories system
to the MultiPro.
Note: The maximum amount of tubing
that can be used with the manual sample
draw kit is 50 feet.
3.1.1 Manual sample draw kit usage
To use the manual sample draw kit:
1. Connect the short section of hose that
comes off the squeeze bulb to the
sample draw adapter.
2. To test the seals in the sample draw
system, cover the end of the sample
draw probe with a finger, and squeeze
the aspirator bulb. If there are no leaks
in the sample draw kit components, the
bulb should stay deflated for a few
seconds.
3. Secure
the
calibration
adapter (with the
sample draw
assembly
attached) to the
MultiPro by
inserting the tab
and tightening the
knurled screw into the brass nut at the
bottom of the adapter.
4. Insert the end of the sample probe into
the location to be sampled.
5. Squeeze the aspirator bulb to draw the
sample from the remote location to the
sensor compartment.
To ensure accurate readings while
using the manual sample draw kit, it is
necessary to squeeze the bulb once
for every one foot of sampling hose
for the sample to first reach the
sensors, and then to continue
squeezing the bulb once per second
for an additional 45 seconds or until
readings stabilize. As an example, if
10 feet of tubing is used, it will be
necessary to draw the sample in by
squeezing the bulb continuously for a
minimum of 55 seconds or until
readings stabilize.
6. Note the gas measurement readings.
CAUTION: Hand-aspirated remote
sampling only provides continuous gas
readings for the area in which the probe is
located while the bulb is being
continuously squeezed. Each time a
reading is desired, it is necessary to
squeeze the bulb a sufficient number of
times to bring a fresh sample to the
sensor compartment.
3.2
Motorized sample draw pump
Use only Biosystems
part number 54-49-102 sample draw pump
with the MultiPro.
A motorized sample-draw pump is available
for the MultiPro for situations requiring