Vaisala HMP260 - Manual (Page 17)

HMP260 SERIES
HMP260-U017en-1.5 Operating Manual
1997-11-25 11
a plugged hole
for an Exi-approved
reference meter
HAZARDOUS AREA
SAFE AREA
Fig. 3.7 Mounting the sensor head on a duct or channel
When the sensor head is installed in a duct or a channel, the temperature
difference of the air inside and outside the duct must be small as the sensor
head conducts heat.
3.3. Grounding
A single electrical cable with a screen and three to ten wires is recommended
for power and analogue output/serial bus connections. The cable diameter
should be 7...10 mm.
The screen of the electrical cable must be grounded properly to achieve best
possible EMC performance. Recommended cable shield is done in the cable
gland as shown below.
• remove the brass disks, rubber ring and nut from the transmitter
housing
• strip 165 mm of the cable insulation, but leave 25 mm of the braid
visible
• slip the nut and rubber ring over the cable insulation
• slip the brass disk that has the bigger hole in it over the braid so that
it rests against the cable insulation
• slip the other brass disk over the wires to the middle of the braid