Table 1. BIT Information
Title
Disable Ice
Detection
1
Initiated
BIT
Continuous
BIT
MSO Fail, High
X
X
MSO Fail, Low
X
X
EEPROM Fail
X
RAM Fail
X X
ROM Fail
X X
Watchdog Fail
X
Power Interrupt Timer Fail
X
Power Fault Monitor Fail
X
Probe Heater Always ON or OPEN
Active Test
Passive Test
Probe Heater Always OFF
Active Test
Passive Test
2
Probe Heater ON w/ 1 Enable
X
De-Icing Fail
Clear Only
Set Only
Unknown Reset Failure
X
Ice Output (not contained in 0871KB1 model)
Active Test
Passive Test
Note 1: When the failure is enunciated, the software no longer provides ice
detection capability.
Note 2: In Continuous BIT, the “Probe Heater Always OFF” failure is set
when the heater is ON and a de-icing failure has been detected. If the
frequency indicates that the ice has been removed within the expected time,
the software will not annunciate the probe heater failure. The actual failure is
most likely due to a problem in the heater feedback circuitry rather than heater
control circuitry. The failure will be enunciated the next time IBIT is
performed.
6
Operator-Initiated Tests
The operator can test the freezing rain sensor functionality by
squeezing the tip of the probe between the index finger and
thumb. This simulates icing by decreasing the frequency of the
probe.
With the sensor wired to the datalogger use a digital voltmeter
(DVM); measure DC voltage signal between the Ice signal (blue
wire in control port) and the power reference ground (black wire
in G terminal). The voltage reading should be 4500mvDC to
5000mvDC. When the probe tip of the ice detector is squeezed;
14
