2
Temperature and humidity
Maintain the temperature and humidity in the equipment room at acceptable levels.
•
Lasting high relative humidity can cause poor insulation, electricity leakage, mechanical
property change of materials, and metal corrosion.
•
Lasting low relative humidity can cause washer contraction and ESD and cause problems
including loose mounting screws and circuit failure.
•
High temperature can accelerate the aging of insulation materials and significantly lower the
reliability and lifespan of the device.
To ensure correct operation of the device, the equipment room must meet the temperature and
humidity requirements listed in
.
Table 1 Temperature/humidity requirements in the equipment room
Temperature Relative
humidity
0°C to 45°C (32°F to 113°F)
5% to 95%, noncondensing
Cleanliness
Dust buildup on the chassis might result in electrostatic adsorption, which causes poor contact of
metal components and contact points, especially when indoor relative humidity is low. In the worst
case, electrostatic adsorption can cause communication failure.
Table 2 Dust concentration limit in the equipment room
Substance
Concentration limit (particles/m
3
)
Dust particles
≤
3 x 10
4
(no visible dust on the tabletop over three days)
NOTE:
Dust particle diameter
≥
5 µm
To eliminate corrosion and premature aging of components, the equipment room must also meet
limits on salts, acids, and sulfides, as shown in
Table 3 Harmful gas limits in an equipment room
Gas Max.
(mg/m
3
)
SO
2
0.2
H
2
S 0.006
NH
3
0.05
Cl
2
0.01
NO
2
0.04
Cooling
For heat dissipation, reserve a minimum of 10 cm (3.94 in) of clearance around the device.
Make sure the workbench has a good ventilation system.
