The SVM2 is a handheld static electricity meter used to measure the magnitude and polarity of static charge on objects or surfaces. It is typically held 1 inch (25 mm) from the test surface. On metallic or conductive surface, the meter measures the voltage on the surface. (As with any electrostatic voltmeter, the displayed reading depends somewhat on the size of the object being measured and the distance between the object and the sensor.) On insulating surfaces, voltage is not a well-defined number. In this case, the meter reads a number proportional to the static charge present.
The SVM2 has high sensitivity (resolution), and can detect even a 1 volt charge anywhere within its full range of +29,999 to -29,999 volts. Thus it is easy to measure whether a given process is increasing or decreasing the static electricity present, even if the increase or decrease is by a tiny fraction. The meter reads the actual static signal, but it also captures and stores the highest positive and highest negative signals that were experienced since the last time that the Reset button was pressed. These peak + and can be displayed at any later time.
The peak function has a window time of 0.005 seconds (which is much faster than the display) so even very quick peaks are captured and stored. There is also a user-settable alarm. The alarm will sound if the signal (whether + or -) ever exceeds the value set by the user for at least 0.005 seconds. The alarm can be reset or muted at any time.
With this meter, all of the following can be measured:
- The amount of charge (or voltage) on surfaces and the effectiveness of antistatic processing. Measuring a tiny fractional change in the surface voltage is useful because it tells you whether the problem is getting better or worse as a new remedy is tried and modified.
- The location, strength and polarity of all static sources. Because of the speed of this meter, unexpected sources are easily found.
- The number (per square cm per second) of air ions that are hitting a surface, and the effectiveness of ionizers and discharge devices.
DC Electric field strength in air (also AC, which is 1/3 of the difference between + and peak hold numbers).
- The approximate conductivity or ohms per square of surfaces.
- The approximate attractive/repulsive force between charged surfaces. (This can be calculated from the readings.)
- Voltage differential through the thickness of an insulating sheet or film.
Specifications
- Range at 1 inch: 0 to +/- 29.999 kV (29000 Volts)
- Resolution at 1 inch: 0.001 kV (1 Volt)
- Accuracy: +/- 2% of reading
- Capacitance (to ground) of Sensor: 3 nF
- Sensitivity if used to sense charge: 3.3 kV/nC
- Drift: less than 0.001 kV/ 10 seconds
- Leakage Half Life: more than 10 hours
- Alarm Range: .010 kV to 20 kV / mute
- High-Voltage Alarm: Sounds Automatically, more than 20 kV
- Sample Speed: 0.0005 sec. for 98% response for, 0.015 sec. pulse
- Auto Off: If no buttons are pressed in 10 minutes
- Environmental: -1 to 43 C, 0 to 85% RH
- Size: 115 x 72 x 30 mm
- Weight: 160 g; 5.5 oz
- Battery: 9 Volt Alkaline (~30 hour life) / Low Battery indicator
This meter is not recommended for long-term automated measurements
, such as connection to a data acquisition system. Note that the included output jack is an analog voltage that is 1/10000 of the actual voltage at 25 mm distance. It represents the true waveform including DC and transients (such as AC). The output is intended to be plugged into a multimeter, oscilloscope, or ADC system. This meter should be manually reset at least every 20 minutes in case the sensor had acquired any charge, and at very strong ion levels (if a lot of sparking is present), external ions will add enough charge that the reset must be done more frequently.