DESCO EUROPE
- 2A DUNHAMS LANE, LETCHWORTH, HERTFORDSHIRE, SG6 1BE, UK
Phone: +44 (0) 1462 672005 • E-mail:
, Website:
DescoEurope.com
TB-3076.E
Page 7 of 8
© 2018 DESCO INDUSTRIES INC
Employee Owned
Calibration
Frequency of recalibration should be based on the
critical nature of those ESD sensitive items handled and
the risk of failure for the ESD protective equipment and
materials. In general, Desco Europe recommends that
calibration be performed annually.
In-house calibration can be performed by using
±1 % tolerance resistors in each of the meter's decade
ranges. Connect the resistors to the test leads using
clips and record the meter’s display. Minimise crossing
the test leads when possible. Contact
Desco Europe
Customer Service
should adjustments be necessary.
Special equipment is required to adjust the meter.
Required Equipment
• Digital Multimeter (±1.25 % accuracy @10 VDC and
100 VDC)
• Resistance Decade Box with a range of 10³ to 10
12
ohms (±2 % accuracy @ 10³ to 10
10
ohms; ±5 %
accuracy @ 10
11
to 10
12
ohms)
• Thermometer (±1 °F accuracy)
• Relative Humidity Meter (±2 % accuracy)
• 99 % Isopropyl Alcohol and Cleaning Wipes
Setup
• Test Area
- needs to be free of any high voltage
transformers or power supplies and away from any
type of fluorescent lighting or high power lighting.
• Worksurface
- needs to be covered with a
grounded conductive mat at 1.0 x 10³ or less.
• Technician
- needs to be connected to equipment
ground with a 0 ohm resistor in the ground cord.
• Decade Box
- needs to be connected to equipment
ground.
Normalisation of the Meter
The temperature inside the testing area needs to be
75 °F ±3 °F (23.9 °C ±1.7 °C) at 40 % to 60 % relative
humidity. The meter needs to stay at a temperature of
75 °F ±3 °F (23.9 °C ±1.7 °C) for approximately 1 hour
for proper readings. The meter cannot be normalised
inside objects, enclosed boxes, containers or cases.
The temperature inside an enclosed case will differ
from the outside temperature. These cases will act as
insulators. The meter must remain stationary in the
testing area for about 1 hour without any significant
changes to the temperature.
NOTE: Accuracy is measured after normalising the
meter for a minimum of 1 hour.
Calibration Verification Procedure
1. Use only the test leads that were supplied with the
meter.
2. Use 99 % isopropyl alcohol to clean the two test
jacks located at the top of the meter. Oil from
human fingers can affect the accuracy of the meter.
3. Connect the test leads to the test jacks located at
the top of the meter. Connect the opposite end of
the test leads to a DC voltmeter.
4. Press the red pushbutton. The measured voltage
should start at 10 V ±5 % and increase to 100 V
±5 % at the end of the test cycle.
5. Connect the test leads to the Resistance Decade
Box. Apply the load resistance values indicated in
the table below. The meter should display accuracy
within ±10 % of the loaded resistance value.
Load
Resistance (Ω) Accuracy
Display
Value
Exponent
LED
1 x 10
12
+20 %
1.20 x 10
12
12
-20 %
8.00 x 10
11
11
1 x 10
11
+10 %
1.10 x 10
11
11
-10 %
9.00 x 10
10
10
1 x 10
10
+10 %
1.10 x 10
10
10
-10 %
9.00 x 10
09
9
1 x 10
9
+10 %
1.10 x 10
09
9
-10 %
9.00 x 10
08
8
1 x 10
8
+10 %
1.10 x 10
08
8
-10 %
9.00 x 10
07
7
1 x 10
7
+10 %
1.10 x 10
07
7
-10 %
9.00 x 10
06
6
1 x 10
6
+10 %
1.10 x 10
06
6
-10 %
9.00 x 10
05
5
1 x 10
5
+10 %
1.10 x 10
05
5
-10 %
9.00 x 10
04
4
1 x 10
4
+10 %
1.10 x 10
04
4
-10 %
9.00 x 10
03
3
1 x 10
3
+10 %
1.10 x 10
03
3
-10 %
<1.0 x 10
03
<3
