Suparule Cable Height Meter:A guide

Jan 2012

Key Features:Safest - no contact with conductors/wire Simple -  One button- one man operation Easy to use - stand underneath, press the button, and read the measurementFast - measurements in seconds Accurate - less than 0.5% error in reading

Suparule Cable Height MetersCable Height Meter –an ultrasonic device to check wire clearance to ground and spacing of overhead conductors.

Why was the CHM developed?

• Low wires are a public safety problem• Many reported accidents with both electrical and

telecom wires• Existing measuring methods were not considered

safe enough for operators

Competitive Instruments

• Laser type surveying equipment. (Very expensive, and not application specific)

• Fibre-glass hot sticks (frequently breaks, conveys electricity if dirty/wet)

• Optical device (inaccurate, cannot differentiate between conductors)

• No real competitive instrument to the CHM

Ultrasound Measurement• From the cone of instrument, the transducer sends out a burst of

sound• The sound ‘bounces’ off the cable, and need to be received in

cone, as transducer is at the same time transmitter & receiver.• The CHM clocks the amount of time taken• Calculates distance, based on speed of sound. Adjusts for air

temperature.• The microcontroller calculates the distance in either imperial or

metricInstrument Time Echoes from wires

How to use of Cable Height Meter

     CHM Operation 

1. Select: M (metric) or I (imperial) at the back

2. Set the CAL mode switch to the WIRE

position.

3. Press the ON key to power

4. Stand directly underneath the conductors(s) to be measured.

5.  Press the MEASURE Key to take measurement. Press the READ key to display each of the stored wire height differences (Stored Measurements).

Cable height meter: CAL (Calibration) Mode

• The CAL mode switch allows the user to periodically check the unit, to ensure that it is still operating within specification.

• For cable height measurement, this switch should be in the WIRE position.

• When the switch is put to the WALL (CAL) position horizontal measurements to large objects, e.g. walls, can be taken.

• When the unit is first used, a horizontal reading to an object, e.g. wall, from a fixed position should be taken. The reading should be recorded, together with the date. Whenever the unit is to be checked for accuracy, a reading should be taken from the same point, noting the result and date. If the reading is outside of specification, the unit should be returned to Suparule. Date

Readings

Range Specification of the CHM 190-300-600measures up to 15m (50ft)

Range Specification of the CHM 300E-600Emeasures up to 23m (75Ft)

Cable height meters: Model choice

CHM models 300 300E 600 600E

Range (25mm cable min)

3 –15m (10-50ft)

3 –23m (10-75ft)

3 –15m (10-50ft)

3 –23m (10-75ft)

Range (12mm cable min)

3 –15m (10-50ft)

3 –15m (10-50ft)

3 –15m (10-50ft)

3 –15m (10-50ft)

Range (5.5mm cable min)

3 –12m (10-40ft)

  3 –12m (10-40ft)

 

Range (2.5mm cable min)

3 –10m (10-33ft)

  3 –10m (10-33ft)

 

No. of wires measured

3 3 6 6

Just simply stand under the O/H line, center yourself under the conductors and press the button.

Reading #1 gives the height to the lowest conductor

Reading #2 gives the distance between 1st and 2nd wire

Reading #3 gives the distance between 2nd and 3rd wire

Reading #4 gives the distance between 3rd and 4th wire

The memory stores the measurements so that you can scroll through them in order to record them on paper etc.

By pressing button once, readings of up to 6 conductors are taken provided the wires are all within the ultrasonic

beam

CHM & Ultrasonic beam

• Push Measure button once, provided wires are within the ultrasonic beam.

• If not, take a number of readings underneath each of the wire.

• Make sure the cone is perpendicular to overhead wire, as otherwise reflection will not be received in cone.

CHM Accuracy : Error typically less than 0.5% +/-2digits

• If the actual distance being measured is 5m, tolerance of +/-0.5%, the CHM will give a reading between 4.975m and 5.025m

• The Number of digits specification is an extra tolerance on the display reading. 2 digits = 10mm. The +2d specification therefore means that a further +/-10mm can be added to the display reading, i.e. 4.965m and 5.035m.

• Accuracy is met when CHM is regularly calibrated. Best practice require a 12 month calibration.

CHM Battery

• Battery Life 50,000 measurements • Battery used: 9V, PP3, non-rechargeable, Alkaline,

Long-life (>600mAH)• The cable height meters automatically switch off

after 3mn if no buttons are pressed to save battery.

• When battery is low, a low battery warning symbol pop up on screen: Need to change the battery.

Do & Don’t with CHMDo’s:Position the unit on the ground, directly

underneath the conductor(s) to be measured.

Align the unit in the direction of the conductor, with the cone pointing towards the conductor(s).

The ultrasonic waves need to be sent and received in the cone, so alignment is important.

Keep the unit dry; if it does get wet, leave it upside down in a warm area

The unit will work in a humid environment; however, if water gets into the electronics, long-term damage can occur.

Don’ts:Avoid clutter.

Too many branches/leaves could confuse the unit, as the ultrasonic waves will bounce back from any obstacles.

Avoid water.It can damage the electronics

Avoid sudden changes of temperature. The Cable Height Meter takes into account temperature to measure the speed of sound travelling in air. If there are sudden temperature changes, i.e. from a warm car in winter to cold icy ground, leave the unit to adjust for a few minutes.

Suparule Cable Height Meters : Get the most out of CHMs

1. Let temperature settle, otherwise incorrect reading is displayed.

2. Press measure button until reading is stable. Unit needs to get a clear/clean echo back, to calculate correct distance.

3. Make sure echo gets back into cone, as otherwise, unit will not display reading. May need to tilt unit to get a reading if overhead wires are sloped.

4. CHM is not waterproof, so keep unit dry as much as possible. If wet, leave it in a warm place upside down, until dry.

5. Regular calibration a must to get best accuracy

Who uses the CHM?

• Planners• Safety Officers• Line Managers• Linesmen / Installers• Contractors• Haulage companies• Regulatory Inspectors

Warranty & Repair

• The CHM is covered by a 24 month warranty on all parts and labour

• Any defective instrument will be replaced free of charge during this period

• Damaged or broken instruments will be repaired and charged at cost

• Each instrument is pre-set, and calibrated at Suparule

• Service contract available, please contact your distributor/suparule.

Suparule Cable Height Meters

• No better instrument for wire distance measurement

• Your key partner to safety

• Order NOW