A force transducer is always the same basic idea: a spring element that deforms measurably under load, and strain gauges that translate that deformation into an electrical signal. What separates the designs is not the measuring principle but how the force is introduced and how much space is available. This page sorts the range by the task rather than by the type code.
1. Direction of force
The first question is whether tension, compression or both are measured. A cell designed for compression only cannot measure tension and will be damaged by it.
- Tension and compression: S-type transducers for fitting into a tension line, flange and spoke types for high stiffness at low height, force measuring blocks and rod types.
- Compression only: button load cells where height is tight, column cells for large loads, force measuring rings for measuring around a shaft, machine feet to place underneath.
- Tension only: tension links, rope tension cells and crane scales.
2. Installation space
Where space is short, the design decides everything else.
- Small dimensions – when the transducer has to fit into a fixture, a hand-held device or a machine assembly.
- Bending beams – shear beam, bending beam, double shear beam and single point cells for tank and platform scales.
- Load pins – the pin in the bearing becomes the sensor itself; no extra mounting point is needed.
- Three-dimensional sensors – when the direction of force is not fixed and Fx, Fy and Fz are needed separately.
3. Rated capacity
The range runs from 1 N to 10 MN. Sizing follows a simple rule: the largest expected load should sit at around 70 to 80 percent of the rated capacity. Chosen too small, the cell is destroyed; chosen too large, resolution is wasted – a cell using only ten percent of its range carries the same absolute error as it does at full load.
Dead weights, dynamic shocks, starting loads and off-centre loading have to be counted in. The safe load limit in the data sheet says how far overload is tolerated without lasting damage; the ultimate load says where it ends.
4. Signal
Two routes are open. The classic one is the passive strain gauge full bridge with a rated output in mV/V, which needs an amplifier or transmitter – in exchange the cell is inexpensive, robust and available for a long time. The second route is cells with built-in electronics: IO-Link for a digital connection with diagnostics, analogue versions with 4…20 mA or 0…10 V, or cells with a display for reading on site.
5. Environment and certification
- ATEX and IECEx for hazardous areas.
- IP69K for high-pressure cleaning and wet areas.
- SIL and performance level when the measurement takes on a protective function – which calls for two independent measuring circuits and the reliability figures for plant certification.
6. When no standard design fits
Then it gets built. octogon manufactures custom force transducers, from the design of the spring element through CNC machining to calibration. And where there is no room for a sensor at all, strain gauges are applied directly to an existing component – on site at the plant as well.
What we need for a recommendation
With these six pieces of information a concrete proposal comes back instead of a catalogue list:
- direction of force and largest expected load
- available installation space, ideally with a sketch or photo
- static or dynamic, and how fast
- environment: temperature, humidity, cleaning, hazardous area
- the signal you want and what exists on the control side
- requirements for certification or functional safety
To office@octogon.org or +43 676 362 8453.