For Surface Resistivity Readings:
Place the meter on the surface being tested and press the test button . If the LED showing 10^6. is illuminated, the surface being tested has a surface resistivity of 10^6 ohms per square or less. If the LED labeled insulative, is illuminated, the surface under test has a surface resistivity is greater than 10^12 ohms per square. (Be sure the ground wire is not connected through the ground jack when surface resistivity measurements.)

For Resistance to Ground Readings: 
Place the meter on the surface being tested. Connect the meter to a known ground through the ground jack. When the ground wire is connected through the ground jack, the meter will not measure surface resistivity. Press the center button and the illuminated LED will indicate the resistance 10^5 ohms or less. If the LED shows insulative ,the resistance to ground of the surface under test is greater than 10^12 ohms.

Product Features:

• measures both surface resistivity and resistance to ground
• easy to use, no cable or probes to adjust
• extended range of direct readings in ohms per square for surface resistivity measurement and in ohms for resistance to ground
• portable - uses 9-volt battery (not included)

• range: automatic from 103 Ohm/Sq to 1012 Ohm/Sq
• display: LED's - one per decade and insulation
• accuracy: ± 10%
• changeover point: 1/2 decade on a logarithmic scale (3.16 x 10n)
• changeover point accuracy: ± 1/2 decade
• power: 9 V battery (not included) (battery life over 40 hours of continuous use)
• dimensions: 2.76" x 0.98" x 5.12" (70mm X 25mm X 130mm)
• weight: 6 ounces (170g)