by Danielle Hiltz
As ergonomists, one of the most frequently used tools in our tool kit is the force gauge. We use it to measure push and pull forces, and object weights. Therefore, when it comes time to purchase one, we have to carefully consider whether to go with a digital or analog instrument.
If you have ever seen one of our ergonomists collecting data in your facility you might have noticed them using an instrument that looked a little bit ancient. This instrument is not an antique – it is an analog force gauge! Most of ours are beat up from years of pushing, pulling, and being carried around all day in our tool belts. All force gauges require calibration every year, so as long as they pass their annual test (and a check every once in a while in between calibrations), we keep them!
In the world of digitization, we have been conditioned to think that digital technology is always better. However, when it comes to force gauges, this may not be the case. Digital and analog force gauges do essentially the same thing. The decision to choose one over the other should be based on the environment and context in which you are going to be using it.
So why do our ergonomists at Taylor’d Ergonomics prefer analog force gauges? We always say that we aim to use leading-edge technology, so analog-anything seems inconsistent with this goal.
Here are some of the reasons why an analog force gauge better fits our ergonomists’ needs:
- The analog force gauge does not contain any electrical components. This is an advantage as we never have to worry about the battery dying during a long day of data collection. We often have a very limited amount of time to gather all the information we need about a job, so we can’t afford to have a dead battery just at the time when we need the gauge! It also means that our ergonomists don’t have to carry a charger or a spare battery around, which helps to lighten the load, as we always bring everything everywhere!
- Some of our clients require us to assess jobs that take place in hazardous or temperate environments where it is safer to use instruments with no electrical power.
- The analog force gauge is longer than most digital force gauges and has a rounded shape that better fits the anthropometrics of the hands. This allows our ergonomists enough room to use a one- or two-handed power grip when assessing pushing, pulling, and lifting forces. The Shimpo force gauge that most of us use right now measures up to 50 kg of effort; when assessing jobs that require pulling, pushing, or lifting heavy loads, we need a good grip on the force gauge. Sometimes two hands are needed.
- An analog gauge is simple and easy to use, with a dial and one push button to switch between settings. This allows us to easily explain the gauge to workers, so they can help us to obtain force measurements. Having fewer buttons on the surface where the gauge is held minimizes the chance of the setting being altered when obtaining a force measurement.
- Finally, the analog force gauge allows the ergonomist to view the change in force during the task, in real time. While a digital gauge might record this data, it is almost impossible to watch “change” on a digital display. When measuring initial and sustained force to push a cart, for example, we can see the peak force on an analog display, and then we can see when the force drops after the cart gets moving. On a digital gauge, these readings would be recorded, but it might be harder to correlate with a change in direction, or the crack in the flooring, or other things that we could “see” while obtaining the readings. If something bumps or jolts against the gauge, the ergonomist will see that and will know to disregard the reading.
An analog instrument does have its drawbacks:
- It is susceptible to parallax error, a measurement error that occurs when the user of the instrument misreads the measurements because of the angle at which the measurement was read. (If you read the speedometer from the passenger side of an older car with an analog gauge, you might judge your speed slower than what the radar gun reports.) Ergonomists who are aware of this error read the gauge “straight on”.
- It has no memory – the ergonomist has to record the readings immediately after taking them. (But with a digital gauge, the ergonomist still needs to know which reading represents which task!)
If you’re shopping for force gauges, weigh the pros and cons carefully before committing to a purchase!
Want to learn more about using force gauges? We have spaces available in our September 8-9 PDA/CDA workshop!