There are various makes of cable tensiometers but the most well used in the commercial aviation industry is called the Pacific T5 model. This is a compact instrument Which is packaged in a box to protect it with three raisers for different cables and two charts, one for British and one for American cables. These two charts both have the Tensiometers serial number printed on them. It is of utmost importance that the correct charts are used as they are calibrated for the actual instrument.
NEVER EVER SUBSTITUTE A CHART FROM ANOTHER INSTRUMENT AS THIS WOULD GIVE AN INCORRECT READING AND COULD IMPAIR AIRCRAFT CONTROLLABILLITY WHEN IT IS OPERATED.
This type of tensiometer is calibrated by the dead weight method. The average of four readings is used. This reading must be within one point (plus or minus) for the chart to be certified calibrated, If the chart is out of tolerance it must be redrawn and re-certified.
The operation of this instrument is straightforward.
- i) Refer to the chart (check the serial number) and select the correct riser for the cable
- ii) Fit the riser
iii) Lower the raiser (Pull handle away from the aluminium body)
- iv) Place cable between body and the two raised hardened steel pins/blocks
- v) Pull lever/handle to the body until it makes contact with the body of the tensiometer
- vi) Set brake lever (Rotate 180 degrees)
- vi) Release handle lever
vii) Take reading.
viii) Compare reading against riser and cable size and temperature on the calibrated charts.