PS-2111
Page 4 of 7
12 ±3% RH and 50 ±5% RH and
temperature to 23 ±1 degrees C)
• Specimen support surface (For
example per S4.1 greater than 1.0 x
10E12 ohms such as PMMA, PTFE
or polycarbonate)
• Specimen Pre-Conditioning (For
example per S4.1 at 23 ±1 degrees C;
3 specimens at 12 ±3% relative
humidity for up to 72 hours
minimum, and 3 specimens at 50 ±5%
relative humidity for up to 72 hours
minimum)
• Reporting Test Results, for example
per S4.1 Reporting Test Results,
Report:
• Minimum, median and maximum
readings for both resistance-to-
groundable point and point-to-point
resistance in ohms at low relative
humidity
• Minimum, median and maximum
readings for both resistance-to-
groundable point and point-to-point
resistance in ohms at moderate
relative humidity
• Temperature
• Relative humidity
• Actual duration of conditioning
• Test equipment used
Periodic Checks of Installed
Product Test Procedure
Guideline
The ESD Association lists test
procedures and troubleshooting tips in
Compliance Verification ESD TR53.
Measure RTG Resistance to
Ground
Test Procedure in accordance with ESD
S4.1 paragraph 6.4 Periodic
Worksurface Testing:
• Do not clean the surface
• Remove from the surface only those
items that might interfere with the test.
• ESD sensitive devices shall also be
removed
• Clip the sensing test lead with
shielded plug to groundable point
connected to ground
• Use one 5# Electrode on other test
lead and place Electrode the farthest
convenient point on the surface
• Press button and hold Test Button
until measurement is displayed
• Perform additional measurements
placing Electrode on the most
commonly used or most worn area
If measurement is outside acceptable
limits, clean surface and retest to
determine if cause of failure is
insulative dirt layer or the ESD
protective product. Note: Use an ESD
cleaner containing no insulative silicone
(i.e. Reztore™ Antistatic Surface and
Mat Cleaner).
Reporting and Using Test
Results
Different standards have different
requirements; use requirements as
specified in user's ESD control plan.
Examples are:
Per ESD 4.1 (worksurfaces), Report:
• RTG maximum and minimum values
measured for resistance-to-ground
• RTT maximum and minimum values
measured for point-to-point resistance
in ohms
Per ESD 7.1 (floors) Report:
• RTG all values in ohms for resistance
to ground
• RTT all values in ohms for point-to-
point resistance
• Voltage level
• Test date
• Temperature
• Relative humidity
• Test equipment used
Summarize test data by reporting
minimum, maximum, median, and mean
values obtained. Include a diagram
showing approximate electrode
positions and ground connections used.
Recommended Frequency of
Periodic Checks of Installed
Products
Note: "The frequency of periodic testing
is normally specified in corporate
operating procedures. …The frequency
of testing is driven by the amount of
risk exposure that can occur between
tests. For, example, what is the quantity
of product handled between test
periods?" (See ESD Handbook TR
20.20) However, a common guide
would be:
10"
© 2007 DESCO INDUSTRIES INC.
Employee Owned
Figure 3. Setting up for RTG testing.
Measure RTT Resistance
Between Two Points on the
Surface
• Do not clean the surface
• Remove from the surface only those
items that might interfere with the
test.
• ESD sensitive devices shall also be
removed
• Use two 5# Electrodes, place in the
most commonly used portion of the
surface 10" apart (2" from any edge,
3" from any groundable point)
• Press button and hold Test Button
until measurement is displayed
• If the most used portion is not
obvious, use two points near the
center of the surface
If measurement is outside acceptable
limits, clean surface and retest to
determine if cause of failure is
insulative dirt layer or the ESD
protective product. Note: Use an ESD
cleaner containing no insulative silicone
(i.e. Reztore™ Antistatic Surface and
Mat Cleaner)
Figure 4. Setting up for RTT testing.
