Model MER Clamp-on Digital DC Ammeter with Magnetic Error Correction by Swain Meter

Model MER Clamp-on Digital DC Ammeter with Magnetic Error Correction by Swain Meter
Ship to
Shipping Method
Estimated Delivery
No shipping options


The Swain MER DC Amp Clamp Meter features manual range selection and manual zeroing. MER stands for Magnetic Error Reduction which allows the meter to quickly measure the magnitude and direction of DC current on any conductor.

Data logging jacks are a standard feature on the MER Meter. Recorder connector with 0±2 V full scale output, plus overrange.


  • Optional external battery operation.

  • Measures direct current without interrupting the circuit. 

  • Magnetic Error Reduction (MER) type Clamp DC Ammeters™ are generally more accurate for measuring direct current with a non-contact sensor. They are constructed to substantially reduce zero offset error due to non-uniform magnetic fields common on steel pipe, near rebar, or near the battery in cars and trucks. The benefit is usually two or three to one over comparable standard Swain Meters. 

  • Offshore platform anode current or transmission line current can be measured at 700 ft. depth or more. MER™ DC Clips (to 6" dia.) and Clamps (to 82" dia.) work undersea for a long time when waterproof connectors are provided. 

  • Accuracy is ±1% reading, ±3 digits, ±He*. User friendly 31/2-digit LCD meter with polarity and 1/2"-high numerals. 

  • Protected from 300 A overload. 

  • AC input current is rejected to less than 5 mA change with 10 A input. 

  • Portable, with auto off, or full on for recorder, 50 hr. typical alkaline internal battery life. Test Battery range provided. 

  • * He is zero offset sensitivity of the sensor to the earth's magnetic field. The earth field is uniform unless steel is close and distorts it. A strong magnet nearby can also cause zero offset. 

  • 3/4" Clips to 82" dia. Clamps, which work in a desert, or 500 ft. under water with optional waterproof connectors and extensions.