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TESTING
for static control floor finishes
EQUIPMENT:
(1) A properly calibrated
megohmmeter having a nominal open circuit voltage of 500 volts and a short
circuit current of 2.5 to 10 mA capable of reading resistance from 0.000 to 1000
M ohms (0.000 to 1,000,000,000 ohms).
(2) Two metal
electrodes with terminals for making connections to the ohmmeter. Each electrode
shall weigh, 5 pounds +/- 1 ounce, and shall have a dry, flat circumference
contact area of, 2.5 +/- 0.062 inches, in diameter.
ELECTRODE PREPARATION: On a flat hard smooth surface, place a
piece of aluminum or tin foil (0.0005 to 0.0010 inches thick). On top of the
foil, place a layer of rubber 2.5 inches in diameter and 1/4 inch thick and
having a hardness of 50 +/- 10 as determined with a shore type A durometer.
Place the electrode on top of the rubber pad, draw the foil up around the rubber
layer and the electrode and secure the foil with a rubber band or pressure
sensitive tape. Repeat this procedure for both electrodes.
TESTING resistance to
ground:
Connect the ground lead (without electrode) of the test instrumentation to the
ground point and place the positive lead connected to the electrode on the
surface of the material tested. Set instrumentation to 500 volts DC. Apply test
voltage and record the resistance after the measurement has stabilized or after
a maximum of 15 seconds has elapsed. Repeat this procedure for different ground
connections. Perform testing at ambient humidity. Test at each ground.
TESTING, point to point:
Connect the leads of the test instrumentation to the electrodes. Set
instrumentation to 500 volts DC. Place electrodes on the surface of the material
to be tested approximately three (3) feet apart. Apply test voltage and record
the resistance after the measurement has stabilized or after a maximum of 15
seconds has elapsed. Repeat this procedure while performing 5 tests per 1000
square feet of the surface. Perform testing at ambient humidity. Perform at
least 5 tests per 1000 square feet.
RESULTS OF TESTING: Static control flooring should be less than
1x109 ohms. Report all values in ohms for both resistance point to
point or resistance to ground. Record the voltage level, test date, temperature
and the relative humidity. Record the type of equipment used. |
