Dwyer Instruments PMT2 Serie Installation Und Betriebsanleitung Seite 2

The PMT2 utilizes a highly reliable DC coupled electrostatic induction sensing
or stack. The inductive effect takes place when particulate passes near the probe
processes the signal into a output that is linear to the mass concentration of particulate.
The PTFE coated probe ensures reliable operation with all types of particulate including
moist powders and highly conductive dusts. The PTFE coated probe eliminates the
need for an air purge and keeps maintenance to a minimum.
baseline reading is application dependent and should be measured independently for
each installation. From this baseline the operator will monitor output signal from the
PMT2. The increase in mA output indicates a rising level of particulate in the air stream
The PMT2 is designed to give a proportional output based on the particulate levels in
a duct or pipe, it is not designed to output a signal based on the particulate volumetric
particulates with low charge properties or high charge properties. As a reference, Table
1 lists particulate charge properties and the suggested range.
Particulate
Human Hands
Asbestos
Rabbit Fur
Acetate
Glass
Mica
Human Hair
Nylon
Wood
Fur
Lead
Silk
Aluminum
Paper
Neutral
Steel
Wood
Mylar™
Nickel/Copper
Silver/Brass
Gold/Platinum
Sulfur
Acetate Rayon
Polyester
Styrene (Styrofoam)
Acrylic
Saran™
Polyurethane
Polyethylene
Polypropylene
Vinyl (PVC)
Silicon
PTFE
Silicone Rubber
5 to 5000 pA
5 to 1000 pA
5 to 500 pA
5 to 100 pA
5 to 500 pA
5 to 1000 pA
5 to 5000 pA
Remove the PMT2 from the shipping carton and inspect for damage. If damage is
found, notify the carrier immediately.
The following factors should be considered when determining the installation location
for the PMT2:
bar).
• Make sure the 4-20 mA signal wires are not sharing the same conduit with high
voltage power wires.
• Make sure the location the transmitter is mounted in meets the NEMA or IP rating
for the enclosure.
• Locate the transmitter in a location were it can be accessed in case service is
required.
The PMT2 should be mounted in a grounded metal stack, pipe or duct. It should not
reach 1/2 to 2/3 the way across the stack, pipe or duct to ensure accurate readings.
For the most stable and accurate readings it is recommended to mount the PMT2 in
close to blowers and dampers that cause turbulence. It is ideal to mount the PMT2 in
an area with two upstream duct diameters and one down stream duct diameter that
are free of turbulent causing objects. The sensing probe is coated in a non-stick PTFE
preventing material from coating the probe reducing the need for cleaning or an air
purge.