This is a very important tool for the electronics technician. Capacitors (mostly electrolytic) are very often the cause of failure with many devices. A these capacitor may test well within tolerance when checked with a capacitance meter, the capacitance setting of your DMM or when checking them with the resistance settings of an analogue meter, but these meters will not measure the ESR or Equivalent Series Resistance of the capacitor being tested. The ESR may have become very high even though the capacitance checks within tolerance on a capacitance meter and the capacitor seems to charge fine with the analogue meter, as a matter of fact this is very common, that is why the ESR meter is a necessary tool.

Not to say the DMM and analogue meters don't have there advantages too, they are also very useful along with other types of test equipment as well.

 

 

ESR

Practical capacitors and inductors as used in electric circuits are not actually ideal components only contributing capacitance, inductance and reactance to a circuit. They can however, be treated as ideal capacitors and inductors in series with a resistance, this resistance is referred to as the equivalent series resistance (ESR). There are also other characteristics such as equivalent series inductance(ESL), leakage resistance and more which we will not discuss here. The physical origins of ESR are dependent upon the device in question. In a non-electrolytic capacitor the metallic resistance of the leads and electrodes and losses in the dielectric comprise the ESR, in an electrolytic capacitor the resistance of the electrolyte also makes up a portion of the ESR. A very serious problem, particularly with aluminum electrolytic capacitors, is that ESR increases over time with use. Very often ESR in electrolytic capacitors  increases enough to cause circuit malfunction even though the measured capacitance may remain within tolerance. While this happens with normal aging, high temperatures and large ripple current exacerbate the problem. In a circuit with significant ripple current, an increase in ESR will increase heat dissipation, hastening the the capacitors failure. The ESR meter is so valuable because it allows you to quickly check the many electrolytic capacitors found in electronic devices for raised ESR and very often you can test them in circuit all though if you ever doubt the reading it never hurts to test the capacitors out of circuit or at least  unsolder and lift one of the capacitors leads from the circuit. When capacitors are in parallel with other capacitors which is very typical for instance in the secondary output filter circuitry of a switching power converter they must be removed from circuit to get an accurate reading. 

 

 

 

 

 

 

The BLUE ESR Meter Fully Assembled With Upgraded Test Leads

 

    

BLUE ESR meter professionally assembled, tested and calibrated by Preher-Tech, includes a 9V battery and comes with professional grade test leads the same as or comparable to the ones shown in the picture above

$125.00

In Stock

Price includes USPS Priority Mail shipping for all orders within the contiguous United States

 Orders typically ship within 24-48 hours of purchase

Click here to download the user's manual 

The BLUE ESR Meter Fully Assembled With Stock Test Leads

BLUE ESR meter professionally assembled, tested and calibrated by Preher-Tech, includes a 9V battery and comes with stock test leads

$110.00

 Orders typically ship within 24-48 hours of purchase

Click here to download the user's manual 

The BLUE ESR Meter Kit

BLUE ESR meter kit, includes a 9V battery

$85.00

 Orders typically ship within 24-48 hours of purchase

Click here to download assembly guide and user's manual 

Save and print the ESR value chart below

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If you have any questions or concerns please email us at contactus@preher-tech.com