# How to Measure Pounds of Force With Digital Pressure Gauges

One way to measure pounds of force, such as in a hydraulic press system, is to use a digital pressure gauge with a custom multiplier feature. So before you get started, make sure you have a gauge that is equipped with this feature.

Let’s say you are using a metal stamping machine and you want to measure the pounds of force being exerted by a ram with a diameter of 5 inches. The gauge you have tapped into the hydraulic lines has a range of 1000 psi.

Calculate the Surface Area

The first step to determine the multiplier is to calculate the area of the ram. The formula for this is area equals pi by the radius squared (A = πr²). So we multiply π by 6.25 inches (radius of 2.5 inches²) to get 19.625 square inches.

Convert to LBF with PSI to LBF Formula

The formula to calculate the LBF multiplier is LBF/inches² = PSI. Since we have the PSI (1,000 psi gauge) and the inches², we use a little algebra to solve for LBF. So we multiply 19.625 by 1000 to get 19,625. This means that when the gauge is reading 1000 psi, you will know that the total force being exerted by the ram is 19,625 pounds.

Divide by Full Scale Range to get the Multiplier

Finally, to get the multiplier that you will enter into the gauge, you will take the total LBF and divide this by the full scale range of the pressure gauge. So 19,625/1000 = 19.625. In this case the multiplier that you will enter into the gauge is actually just the area of the ram. Pretty cool, eh?

Once you have the multiplier, enter that into your digital pressure gauge. This will convert the unit of measure into LBF. Let us know if you're having difficulty with this. We're happy to help!

Automation Products Group, Inc. manufactures pressure transducers and digital gauges. Their line of PG digital gauges is equipped with multiple standard and custom units of measure. To read how to enter a custom multiplier into the PG7 digital pressure gauge, click here.