Chapter 4
– Service, Configuration & Testing
25
FT742-DM (4-20mA)
– Sensors
- User Manual
Cleaning:
The measurement cavity has a super-hydrophobic coating which helps to prevent water building up.
When water enters the measurement cavity the surface helps to wash away dust and debris which may have
settled. If any debris is present this can be removed by gently rinsing the measurement cavity surface with
distilled water using a laboratory wash bottle or similar. Please note excess water droplets can be removed by
lightly blowing or shaking the sensor.
Do not scrape or scratch the surfaces whilst rinsing.
Under no circumstances
should objects be inserted
inside the measurement cavity, as this can cause irreparable damage. If the coating has been damaged then it
may need to be reapplied. The body of the sensor can be washed if required using the same method as
described above. Whilst washing the sensor care must be taken not to get water in the breather hole or into the
connector at the base of the sensor.
Do not use cleaning chemicals to clean the sensor. If washing a nearby item protect the sensor with a suitable
cover. Ensure the cover is removed before re-enabling the wind data survey.
The following replacement parts are available:
FT027
O-ring (3.53 CS x 32.92 ID)
FT031
Size Adaptor 25mm (1”) for FT742-DM (includes a FT033 tapered pipe insert & 4x FT034
self-locking fasteners)
FT032
Size Adaptor
50mm (2”) for FT742-DM (includes a FT033 tapered pipe insert & 4x FT034
self-locking fasteners)
FT033
Tapered Pipe Insert (33.7mm OD)
FT034
1x Self-locking Fastener
FT035
Grounding Accessory
4.2 Fault Finding & Troubleshooting
To determine whether a sensor has a fault carry out the following steps;
•
Follow the inspection procedure above to identify signs of physical damage.
•
Remove any objects or insects lining the cavity or blocking the airflow.
•
Restart the sensor (power-cycle the unit if necessary).
•
Test that the sensor is communicating properly using the Acu-Test Evaluation Pack (see Section 4.4).
If there are signs of physical damage and/or the sensor is failing to communicate properly, it should be replaced.
If required, sensors may be returned to FT Technologies for further analysis (see Section 4.3).
•
A current probe may be useful to monitor the current supply and the 4-20mA current loops.
Warning
– The sensors contain no user serviceable components. Do not attempt
disassembly as damage may result and product warranties will be invalidated.
During extreme weather conditions, there may be periods where data is temporarily unavailable. However there
are ways to mitigate against these affects. The following steps should be taken to ensure the highest levels of
data availability from the sensor:
•
Using the Acu-Test Evaluation Pack (see Section 4.4)