The Line EMI Meter EM100 measures electromagnetic interference in a single-phase AC power line. It plugs into a wall outlet (mains socket), requires no battery, and immediately displays total line noise in millivolts peak to peak (range 1999.9 mVp-p, resolution 0.1 mVp-p) in the frequency range 10 KHz – 10 MHz (the frequency limits at which sensitivity is ½ of the maximum sensitivity).
An internal speaker allows you to hear much of the EMI which can be useful in identifying the source. This is done through amplitude demodulation; but very high frequency noise can be present and inaudible due to being outside of the audio range. AM or shortwave radio stations can often be picked up directly on the line and the broadcasts can be heard through the speaker, as well as the whine from electric motors, static bursts that represent transient noise, and the modulated patterns from Switch Mode Power Supplies (SMPS). SMPS are found in computers, TVs, phone chargers, ect.
Power generation equipment (such as solar inverters) can also often be a source of line noise.
| Specifications |
TriField® Power Line Meter Model PLM |
| Line Voltage Measurement |
|
|
|
Operating Voltage |
85-300 VAC 50/60 Hz |
|
Reading Range |
85-250 VAC |
|
Reading Accuracy |
±3% |
|
Power Supply Cord |
ord (rated to 110V for North America) |
| Line Noise Measurement |
|
|
|
Range |
0.1-1999.9 mVp-p AC (differential) |
|
Accuracy |
±8% @ 20 kHZ to 2 MHz; within a factor of 2 from 10 kHz to 10 MHz |
| Physical Specifications |
|
|
|
Size |
5.2 x 3.6 x 1.6 inches; 132 x 91 x 41 mm |
|
Weight |
8 oz |
