How to Choose an ESR Meter?

Servicing the capacitors on your power conditioners and electric appliances is the easiest once you have a reliable ESR meter for the job.

An ESR meter can tell you so much about the capacitor’s health- eliminating the chances of sudden power failures and device malfunctions.

That said, you need to have the right ESR meter for measuring equivalent series resistance for capacitors. But how to choose an ESR meter?

Below we are pointing out some important facts and features of best ESR meters, and they will help you decide exactly what to look for!

Understanding ESR

Before getting to the part where we discuss how to choose an ESR meter, we would like to brush up on the whole ESR issue. For starters, it is one of the most common and practical resistance measuring instruments for electronics.

The real advantage of ESR meters is not only their compatibility with capacitors but also their broad range of applications. Other than using an ESR meter, you may turn to a DC milliohm meter, a capacitance meter, or an LCR meter for measuring resistance.

What most people don’t get is that no other measuring instrument is as straightforward as an ESR meter. In fact, a capacitance meter- a test used for checking a discrete capacitor’s capacitance is not a dedicated device for measuring resistance.

Only on some occasions do they measure additional parameters such as ESR and leakage. The accuracy is not top-notch either. Similarly, a milliohm meter is just as ineffective as a capacitance meter when it comes to checking the equivalent series resistance.

Its largely because a consistent DC flow does not pass through a capacitor to provide a reasonable reading on multi meters. By this point, you already know that only an ESR meter works well in calculating resistance inside or outside the capacitor.

How to Choose an ESR Meter

Here are the things you need to keep in mind while purchasing an ESR meter.

Compatibility with Capacitors

Compatibility with Capacitors of ESR Meter

ESR meters are so versatile that their applications go way beyond capacitors. To begin with, an ESR meter finds short-circuits in between two PCB tracks. It can also detect a short-circuit location from one capacitor group to the next.

The same goes for parallel transistors. Another reason why we prefer capacitors over other electronic measurement devices is that it provides meaningful readings. You can compare the results to an ideal ESR chart and see where you’re standing with the capacitor.

What we are trying to say is interpreting ESR readings is an easy job. In some cases, it’s quite intuitive too. After all, troubleshooting day-to-day circuit problems are where an ESR meter excels.

Techniques of Measurement

Most ESR meters incorporate a simple, easy-to-use measurement technique. To begin the test, you have to discharge the capacitor entirely.

After that, send a quick flow of electricity inside the capacitor so as to not charge it too high. The results are shown on the ESR meter display in milliohms or ohms.

It is, of course, a simplified manual, and we kept it this way for everyone’s convenience. Now, we love the fact that an ESR meter is an uncomplicated measuring instrument for your electronics.

But, did you know that you don’t have to do any amount of soldering beforehand to get the circuit out of the box? That’s right; an ESR meter will never require that you remove the capacitor from a practical circuit to take a quick reading. How convenient is that?

Maintenance & Care

Without a top-notch oscilloscope, a digital multi meter, and an ESR meter, a technician’s toolbox is as good as empty. ESR meters help detect circuit problems- offering you low-cost diagnostics to care for your electronic equipment.

Once capacitors are fried, it takes a serious amount of servicing before your equipment is ready for use. Untended capacitors erratically disrupt current like resistors. And sometimes, installing a new capacitor is the only way out.

A common example of this problem is when the compressor on your AC or refrigerator makes a prolonged clicking sound. It is one of the signs of a failing capacitor.

This is where it gets more interesting- checking the compressor using only a capacitance can reveal satisfactory capacitance levels. And seeing this might prompt you to put away any real servicing till a later time- damaging your electronics further in the process.

Moving on, an ESR meter is a sensitive device. High voltages from a capacitor on a live circuit can cause permanent damage to the ESR meter. Safety diodes can minimize the damage to some extent.

But you still won’t be able to check a battery’s internal resistance- a special feature of ESR meters that go beyond the common capacitor use.

Multipurpose Use

Just when you thought that a plain old ESR is limited to measuring capacitor resistance, this handy gadget is here with more surprises. For starters, it calculates a low amount of series resistance for diagnosing common circuit problems.

You’ll be surprised to know that most batteries lose their energy, not because of low EMF but because their internal resistance is off the charts. Lucky for you, an ESR meter is used so easily measures the internal resistance present in batteries so that you can extend the battery life.

As far as durability goes, no specialized measurement instrument is safe, like an ESR meter. These instruments cannot produce the perfect, low voltage that doesn’t meddle with the meter readings when semiconductor junctions switch back on.

The fact that most multi meters and ohmmeters use a slightly higher voltage than an ESR meter makes them unsuitable in measuring low series resistance.


Although electricians frequently use an ESR meter, it is not your all-purpose measurement gauge for diagnosing every circuit problem there is.

For example, if you use it instead of your milliohm meter to take a transformer‘s resistance, let us tell you, it’s not going to go anywhere.

If there is a lot of inductance in between its test probes, the measurements are quite meaningless. The reason why it happens is that transformer windings have inductive properties that mess up ESR readings.

Finally, ESR meters effortlessly calculate low capacitor resistance, internal resistance in batteries, printed circuits, and switches. Although nowadays, a combo gauge will give a reading for anything, we love an ESR meter for its accuracy, gentleness, and straightforward use!

Final Words

That’s all we had to say on how to choose an ESR meter. Let us know if you liked our article.



Leave a Comment