AE-780 Operation Manual Rev. 11/30/12 MKB
TEST VOLTAGE
The test voltages are 10v and 100v. According to ESD Association (ESDA) standards
S4.1 and S7.1, 10v should be applied to surfaces with resistivity of less than 106and
100v should be applied to surfaces with resistivity of 106or greater. The AE-780 will
automatically simulate the proper voltage according to the test measurement.
As defined by the ESDA, values indicate the following:
Voltage Range Definition
10 volt < 106ohms per square Conductive
100 volt 106– 1011 ohms per square Dissipative
100 volt > 1011 ohms per square Insulative
A NOTE ABOUT VOLTAGE
In previous years, those desiring to measure resistivity or resistance followed the ASTM
D264, ASTM 991, NFPA 56A or NFPA 99 test standards. These procedures required
one to test at either 500 or 1000 volts. This caused concern regarding safety of the
person performing the tests. The ESDA standardized the test procedures so that lower
volts could be used within specific ranges.
The AE-780 meter uses a 9-volt battery. Some meters with 9-volt batteries do not give
the accuracy needed to perform the tests, especially at values higher than 107. The AE-
780 is built with a transformer that converts the 9-volt charge from the battery to 10
volts or 100 volts. The meter applies a constant charge over the complete voltage
range. Accuracy depends on applied voltage, temperature, and humidity.
TEMPERATURE AND HUMIDITY
Ambient humidity and temperature affect the electrical properties of the material being
tested. The combination of low humidity and low temperature will give the highest
electrical resistance results and slowest dissipation times. At high humidity, a thin layer
of water is condensed on or absorbed into the material being tested. This is true of
hydroscopic additives that are incorporated into a material in order to increase the
electrical conductivity. These additives will allow moisture to be absorbed into the
materials to which they are added.
At elevated temperatures, the mobility of free electrons increases, thereby also
increasing a material’s conductivity. This is especially true for carbon black, metallic
oxides, metals, and other substances. When the material is at a lower temperature,
built‐in stresses occur which may increase resistance due to increased distance
between the conductive additives. Thus, humidity and temperature must be known.
Eastern Energy Co., Ltd. Tel: 66-3844-611
Banbueng, Chonburi, Thailand www.eastern-energy.com
www.eastern-energy.net
