F-1
Appendix F. SR50ATH Heater
Operation
The heater option on the SR50ATH is intended for installations where rime ice
is problematic. The heater will help to prevent the ice from forming on the
transducer, which can impair proper operation of the sensor.
The heater option is easily identifiable as the transducer housing contains a
cable port for the heater supply cable.
Always use the heater option wired to switched 12 Vdc source. For battery-
operated solar-powered sites, Campbell Scientific recommends that the
heater’s power be turned off when icing conditions are not occurring to reduce
power requirements. The heater power must be turned off when operating at
temperatures of 25 °C or more.
CRBasic programs that control the heater are provided in Appendix
(p. B-15)
F.1 Heater Specifications
Heater Resistance:
75
Ω
Nominal Operating Voltage:
12 V (ac or dc); use a properly conditioned,
low-noise power source. A noisy power source
will affect operation of the sensor.
Maximum Rated Wattage:
3 W
Maximum Rated Voltage:
15 V (ac or dc)
Maximum Operating
Temperature:
25 °C; turn the heater power off at
temperatures above 25 °C. This prevents
damage to the sensor and reduces power
consumption.
F.1.2 Heating Cable Requirements
Type:
2 conductor (twisted pair), Shielded
Diameter:
4 to 6 mm (0.16 to 0.24 in)
Recommended Gage:
22 AWG for lengths < 30 m (100 ft)
