Trummeter

TRUMMETER

Precision instrument for measuring belt tension

TRUMMETER

Precision instrument for measuring belt tension

A belt drive achieves its maximum lifetime when it is configured specifically to the application, the belt is perfectly tensioned and the pulleys are precisely aligned.

The TRUMMETER is an electronic measuring instrument that consists of a measuring probe and a microprocessor and is used for measuring the belt tension and checking the strand force of a belt drive.

The measurement result is displayed either in hertz, newtons or poundforce.

This measured value can be compared with the nominal value – specified by the belt drive manufacturer ( as a natural frequency in Hz or a strand force in N ). It is dependent on the characteristics of the drive. Alternative: it can be calculated with this formula :

Product advantages

• Exact measurement of the belt tensioning force

• Exact calculation of the strand force

• Required for recording in accordance with DIN EN ISO 9001ff

• Operator prompts and measured value displays in 10 languages

• Simple and safe operation

• Compact and handy to use

Scope of delivery

The TRUMMETER is supplied in a strong plastic case. Included in the scope of delivery are 2 measuring probes and a 9-V battery.

Measuring the belt tension [Hz]

The belt frequency can be measured only when the drive has been shut down and is stationary. The fitted and taut drive belt is tapped in order to make it oscillate with its natural oscillation. This static natural frequency is then measured by the probe with the aid of pulsed light. Care must be taken to ensure the light is sufficiently reflected by the belt. The measured values are displayed in Hertz [Hz].

Measuring the strand force [N], [lbf]

To calculate the strand force, the frequency, the belt mass and the belt length are entered into the microcomputer, which calculates the actual strand force. The force calculated is compared with the specified value defined when the drive was designed (see additional calculation sheet). The microcomputer calculates the strand force using the formula:

Where:

T = strand force in N

m = linear belt mass in kg/m

L = length of the free belt strand in m

f = natural frequency of the free belt measured in Hz.

Measuring procedure

Measuring steps

1. Switch on the TRUMMETER.

2. Tap the drive belt so that it begins to oscillate with its natural oscillation.

3. Hold the measurement probe approximately at the center of the free strand

length at a distance of 3 to 20 mm above the drive belt.

4. Successful measurement is acknowledged by an acoustic signal and the

indication “Measurement” appears on the display.

5. The measured value is displayed in Hz.

Switching value display mode

The measured values can also be displayed in newtons or in poundforce. Please refer to the section entitled “Menu structure” on Page 5 for instructions on how to switch display mode. If no measurement results are displayed despite careful preparations, this may be due to one of the following two reasons:

1. The drive belt oscillates below the minimum measurement limit of 10 Hz.

Remedy

Tighten the belt or, if the strand length is very long and open, support the belt in order to shorten the strand length. Enter the new belt length before repeating measurement.

2. Either no or low measuring values are displayed despite the drive belt being correctly tensioned.

Remedy

It may be the case that the light from the measuring probe is not sufficiently reflected. To improve reflection, affix a piece of light-coloured adhesive tape to the belt or slightly moisten the belt at the measuring point.

3. The battery must be exchanged when display shows “Low Bat”.

4. The unit will be automatically OFF after pauses longer than 8 minutes.

The distance between the drive belt and the measuring probe should be between 3 and 20 mm. See sketch for positioning.

Important note

Preferably, the belt tension should always be measured at the center of the longer belt strand between the two drive pulleys.

Belt masses

For a display in Newtons or poundforce adjust the device according the menu structure. Before beginning measurement , enter the belt-mass and strand length. For entering the mass see weight-symbol and press this key. Enter the value out of the list below. If not listed refer to the manufacturer’s data sheet, or weigh the drive belt and convert the mass to a value of 1 m belt length. The length which is entered by length key is the value of the existing length between 2 wheels.

Menu structure

Supplied By:

Proviso Systems Limited

Telephone 01777 817536

Facsimile 01777 816045

Email sales@proviso-systems.co.uk

Send mail to dave@proviso-systems.co.uk with questions or comments about this web site. Copyright © 2007 Proviso Systems Ltd. Last modified: 28-04-2008 23:48

Send mail to dave@proviso-systems.co.uk with questions or comments about this web site.
Copyright © 2007 Proviso Systems Ltd.
Last modified: 28-04-2008 23:48