Which force gauge should you choose? Measuring range, resolution and SAUTER FM/FH explained
Compressing a spring, pulling out a cable connection and testing a small plastic fastener are three different measuring tasks. You choose a force gauge by the expected force, the way the load is applied and the information you need from the test. Measuring range and resolution differ per version, and the smallest step on the display is not the measuring accuracy.
1. Decide which force you want to measure
In a tensile test the set-up pulls on, for example, a connection, strip or wire. In a compression test a pressure piece pushes on a spring, button or component. Decide beforehand whether you want to record the current force, the highest force or the force over an entire movement. The shape of the grip or pressure piece matters just as much as the gauge.
A force gauge should preferably display newtons (N). The kilogram (kg) is a unit of mass; the kilogram-force (kgf) is a unit of force. For reference: 1 kgf = 9.80665 N. Always state in a test report which unit was actually used.
2. Choose a suitable measuring range
Estimate the highest force that can occur during the test, including a brief peak at break or release, and choose a gauge with enough range for that peak. At the same time, do not choose an unnecessarily large range if you want to measure small forces with a fine resolution. The permitted force of the test stand, the grips and the adapters must also suit the test.
| Example model | Range | Readability | Load cell |
|---|---|---|---|
| SAUTER FM 10 | 10 N | 0.005 N | Integrated |
| SAUTER FH 500 | 500 N | 0.1 N | Integrated |
| SAUTER FH 5K | 5,000 N | 1 N | External |
These three versions are examples within the FM and FH series. When ordering, check the specifications of the chosen version and the matching adapters.
3. Read readability and tolerance separately
The readability is the step in which the display changes. The stated tolerance describes the possible measurement error according to the product specification. These are different figures: the SAUTER FM 10 reads in steps of 0.005 N, while the manufacturer specifies a tolerance of 0.2% of the maximum range of 10 N. Converted, that 0.2% equals 0.02 N. The small display step therefore does not automatically make an individual measurement accurate to 0.005 N.
Practical example: if you expect around 6 N for a control button, first look at a suitable range and the required measurement accuracy. If you expect a few hundred newtons in a pull-out test, 10 N is far too small. Define the requirement for the complete test before you compare the last decimal place.
4. Integrated or external load cell?
An integrated load cell makes the SAUTER FM 10 or FH 500 compact for handheld use and for mounting on a suitable test stand. An external load cell, as on the FH 5K, gives more freedom to place the cell in a larger test set-up and keep the display elsewhere. Check the permitted force, the mounting and the connection of the chosen combination. How to keep such a set-up comparable is explained in measuring tensile and compressive force reliably.
Frequently asked questions about force gauges
Is a force gauge the same as a scale?
Both often use a sensor, but a force gauge is intended to determine tensile or compressive force during a test. You usually record the result in N, paying attention to direction and progression.
When do I need a test stand?
If tests need to be comparable, a test stand helps control the direction and movement of the applied force. Choose the test stand by the required force, the stroke, the available space and the required speed.
View the available models
Compare the versions by range and accessories, or discuss your test set-up with us.