Not always. A force meter with a large range has scale marks that are far apart, so a lower precision. You choose a meter whose range is just large enough for the force you measure, and within that the highest precision. If the range is too small, the spring stretches too far and the meter is no longer right afterwards.
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A force meter that goes up to a hundred newtons is better than one that goes up to one newton, surely? It can just do more. Even so, you had better not hang an eraser on it.
First you see how a force meter works: a spring with a hook and a scale. The bigger the force, the further the spring stretches, and you read the force in newtons. Then the two words that belong to every force meter. The range is the largest force you can measure with it. The precision is the smallest distance between two scale marks, and tells you how precisely you can read it. An eraser of 0.24 N on a meter up to 50 N does not even reach the first mark; on a meter up to 1 N you read it precisely. Finally you choose a force meter yourself for a pencil case of about 2 N, and you see why a spring that stretches too far is no longer right afterwards.
For secondary school physics, in the chapter on forces. Halfway through there is a question and a pause: stop the video there and think for yourself first.
In this video
The full explanation, in writing
It can just do more
0:00You'd think: a force meter that goes up to a hundred newtons is better than one that goes up to one newton. Surely it can just do more?
A spring with a scale
0:12A force meter is also called a spring balance. Inside is a spring with a hook on it. Pull on the hook and the spring stretches, and the end of the spring slides along a scale. The bigger the force, the further the spring stretches. On the scale you read the force in newtons.
Range and precision
0:32The largest force a force meter can measure is the range. And the smallest distance between two scale marks is the precision: that's how precisely you can read the force. A force meter with a large range has scale marks that are far apart in newtons, and so a lower precision.
0:52Hang a zero point two four newton eraser on a force meter up to fifty newtons, with scale marks every newton, and the pointer doesn't even reach the first mark. On a one-newton force meter, with scale marks every zero point zero two newtons, you read it precisely.
1:12Your turn. You want to measure a pencil case of about two newtons. You have force meters up to one newton, up to five newtons and up to fifty newtons. Which do you choose?
Suitable range, highest precision
1:26It's the meter up to five newtons. Two newtons doesn't fit on the one-newton meter: the range is too small. If you stretch a spring further than it can take, it no longer springs back properly afterwards, and then the meter is no longer right.
1:41On the fifty-newton meter it does fit, but there the precision is too low. So you choose a force meter with a suitable range, and within that, the highest possible precision.
Three things to remember
1:54Three things. A force meter is a spring with a scale: the bigger the force, the further the spring stretches, and you read it in newtons. The range is the largest force you can measure, and the precision is the smallest distance between the scale marks.
2:12And you choose a suitable range with the highest possible precision.
Two questions
2:17Two questions. One. You want to measure a bag of thirty newtons, and you only have a force meter up to twenty newtons. Can you? Two. Two force meters both go up to five newtons. One has scale marks every zero point zero five newtons, the other every zero point one.
2:34Which do you choose, and why?
The answers
2:40The first: no. Thirty newtons is more than the range. The spring stretches further than it can take, and then the meter is wrong after that. The second: the one with scale marks every zero point zero five. The range is the same, and its precision is higher.
Calculating the spring
2:58Do you want to know how to calculate how big the force of a spring is? Then watch the video about elastic force on my YouTube channel.
Frequently asked questions
What is the range of a force meter?
The range is the largest force you can measure with that force meter. A force meter that goes up to five newtons has a range of 5 N.
What is the precision of a force meter?
The precision is the smallest distance between two scale marks on the scale. That is how precisely you can read the force. With scale marks every 0.02 N you read more precisely than with scale marks every 1 N.
How does a force meter work?
A force meter, also called a spring balance, has a spring with a hook on it. Pull on the hook and the spring stretches, and its end slides along a scale. The bigger the force, the further the spring stretches. On the scale you read the force in newtons.
Which force meter do you choose for a pencil case of about 2 newtons?
From force meters up to 1 N, 5 N and 50 N you choose the one up to 5 N. On the 1 N meter, 2 N does not fit: the range is too small. On the 50 N meter it does fit, but there the precision is too low.
What happens if you stretch a force meter beyond its range?
Then the spring stretches further than it can take. Afterwards it no longer springs back properly, and then the meter is no longer right. So you do not measure a bag of 30 N with a force meter up to 20 N.
Choose a suitable range, and within that the highest possible precision.
Physics with Thomas makes physics explainers for secondary school. No words on screen, so what you see works in any language.
In this series
Types of forces3:06
Calculating gravity3:15
Centre of gravity2:48
Force meter: range and precision3:11
Elastic force and spring constant3:41
Directly proportional relationship3:37
About me
My name is Thomas Schuurmans, and I have a passion for physics and for understanding why things work the way they do. What I want is to get young people asking “why is that?” and “how does that work?” more often, and to hand them the tools of physics in a way that is simple and that you can see.
I graduated in applied physics at Delft University of Technology in 2003. After that I spent more than twenty years outside education: first at TNO, the Dutch applied research institute, then at a design agency, and eventually founding Proportion Global, through which I work on innovation questions in Africa, Latin America and South Asia. That work resembles physics more than you would expect: don't start from a solution, first understand what is going on, try something, be wrong, and look again.
Since 2026 I have been teaching physics to both lower and upper secondary classes, and I started a master's at the University of Amsterdam for my full teaching qualification. That is where I learned that a secondary school pupil's real attention for new material lasts about seven minutes. And my own weakness happens to be telling too many side stories.
That is where the idea came from: videos that explain one topic sharply and visually, inside those seven minutes. I make them for my own pupils. Then I publish them, because good explanation should be within reach of anyone who needs it, wherever you live and whatever language you think and speak in.