Potentiometers positions and pressure transducers for bench test

Find out how to check the position in comparative or configuration test benches

Use of power, position and pressure transducers in test benches

The use of position transducers is adopted in test benches used to verify, test or configure a manufactured product.

The transducer allows to:

monitor the movement of one of the mechanical components in real time;
guarantee high repeatability, typically to a tenth of a millimetre;
operate independently of the location of the test benches, in the production flow or in the laboratory;
operate with mechanical, hydraulic or electrical movement.

Overview

Product: LT and PY2 Potentiometric transducers
Request: Control of the position with a repeatability between 0.2 to 0.3 mm.
Result: LT-M or PY-2 gave a feed-back position with a repeatability of 0.1 mm and and high linearity around 0.05% FS

The process

These test benches can have different shapes and are used to verify, test or configure a product.

Some benches are used in the production flow and others are in the laboratory for random checks. In either case, the potentiometers are used not only to obtain a measurement but also to make comparisons with a sample product such as checking tolerances or to detect if the movement is consistent. For example, checking the movement of screw is consistent.

The test benches can be operated either hydraulically, pneumatically or electrically. This choice is at the discretion of the test bench manufacturer depending on the requirements to be detected, the frequency of measurement, the type of test to be performed and the environmental conditions under which the bench is used.

The challenge

For test benches that require real-time monitoring of the movement of one of the mechanical components, an absolute position feedback transducer is considered which can provide the dimension/position immediately on switching on. In addition it guarantees high repeatability, typically to the tenth of a millimetre.

Often the control to be performed over travel of 100-200mm range and the space dedicated to the transducer is limited due to other components mounted around it.

In some situations, particularly where the test bench is in the production line, there may be cooling liquids mixed with particles of metal, wood or stone.

The range of linear measuring products is very wide, starting from small potentiometers with a 10 mm stroke up to transducers with high repeatability even a few metres long.

Product benefits

LT/PC/PY/PZ POTENTIOMETERS

Linear positioning repeatability of 0.1 mm
Theoretically infinite resolution
Linearity: 0.05% F.S.
Real-time output signal
Small mechanical footprint
Strokes from 10mm up to 1000mm

MAGNETOSTRICTIVE WPG/WRG

Analogue output 4…20mA, 0-10Vdc
Signal linearity: 0.04% FS
Theoretically unlimited life time estimation
Strokes from 50mm to 4000mm

Solution

Potentiometric LT / PC transducer 100-200mm stroke (typical specimen size) or Magnetostrictive WPG-A for position control

For short stroke test movement:

Transducer model: PY2 25-50 mm, aluminium profile

For medium stroke test movement:

Transducer model: LT 150-200 mm, aluminium profile

For higher stroke test movement:

Transducer model: WPG-A 300 mm, aluminium profile with floating magnet cursor or sliding magnet cursor