Section 1 - Introduction
6
FT742-DM (4-20mA)
– Sensors
- User Manual
1
INTRODUCTION
1.1 Product Overview
The FT742-A-DM sensor is designed for general meteorological applications - particularly in harsh
environments such as areas of icing, sand, dust and offshore installation. The solid-state ultrasonic wind sensor
uses acoustic resonance airflow sensing techniques to measure both wind speed and direction. The wind
sensor has no moving parts to degrade or wear-out and is designed for applications requiring high reliability.
Mounting and aligning the sensor is simple. A compass (not supplied) can be used to align the sensor with
magnetic North (0°) using the 0° wind datum marking feature (see Figure 12). For operation in ice-prone areas,
the FT742 is fitted with a highly-effective thermostatically controlled all-body heating system. A three-element
heater is used to ensure heat is evenly distributed over the entire surface area.
FT sensors are configurable and can be factory programmed to the required customer settings, contact FT
Technologies for further details.
Note: The FT742-DM range is not suitable for turbine control applications. The FT742-FF and FT742-PM ranges
are designed for this application.
The standard FT742-DM, when installed to FT Technologies recommendations, is electrically isolated from the
mounting pole, making it unsuitable for conductively-grounded lightning protection schemes. The addition of the
FT035 grounding accessory provides a reliable, low-resistance grounding path. Refer to Section 3.3 or contact
FT Technologies for further information.
1.2 Build Versions & Labelling
Figure 1 shows how to identify a sensor, the serial number and calibration code (if applicable). Section 2.2.3
describes how you can use the wind speed scaling reference to identify the calibration of the sensor.
Additional labels may be attached. Only sensors marked with the Intertek label conform to the UL Standard
61010-1 and are certified to CSA Standard C22.2 No. 61010-1.
Figure 1: Examples of Main Sensor Labels
1.3 Scope of Use
The sensors are designed, manufactured and optimised for high availability.
No promise in part or full can be given to guarantee a
wind sensor’s continuous operation, as exceptional
circumstances can occur that may result in the failure of the output from a sensor. Exceptional circumstances
can include;
•
Poor installation
•
Inadequate inspection
•
Power supply failures
•
Poor quality electrical connections
