Desco 19250, Технический бюллетень

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DESCO WEST
- 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Website: Desco.com
4. Lighting of the green “PASS” LED indicates that the wrist
strap and ground cord assemblies are functioning properly.
5. If either red “FAIL LO” or “FAIL HI” LEDs light and the audible
indicator sounds, the wrist strap wearer should check the
wrist strap assembly immediately.
TESTING FOOT GROUNDING DEVICES
When using a Footwear Tester that does not use a split FOOT
PLATE, one needs to test one foot at a time; best practice is to
raise the other foot off the floor. When testing conductive shoes,
or foot grounders worn on both feet, test each foot separately
to test the separate path-to-ground. If the floor is an ESD floor,
placing the other foot on the floor may result in erroneous test
results. Care should also be taken not to create (hand resting on
wall or bench) other paths-to-ground.
1. Press rocker switch toward “FOOT PLATE”.
2. Place one foot on the plate. If the floor is conductive, lift the
foot you are not testing off of the floor during this test. Make
sure there is no cord plugged into the “WRIST CORD” jack.
3. Press and hold the test button until the test results are
displayed.
Calibration
The models 19250 , 19253 , and 19252 are calibrated to NIST
traceable standards. We recommend that calibration is performed
annually to ensure that the Tester is operating within limits. Due to
its dual circuit design both test circuits of the Combo Tester must
be calibrated individually.
Desco offers a calibration unit that is specifically designed to
simplify the calibration procedure. This unit is sold as item
07010 . The Calibration Unit comes calibrated to NIST traceable
standards. For additional information on the 07010 , ask for
Technical Bulletin TB-2039 .
750 Kilohm - 10 Megohm TEST RANGE - WRIST STRAPS
The following resistance should give the display shown:
Resistance Value (±5% or better) Test Output
675 Kilohm Red (Fail Lo)
825 Kilohm Green (Pass)
8.5 Megohm Green (Pass)
11.5 Megohm Red (Fail Hi)
750 Kilohm - 100 Megohm TEST RANGE - FOOTWEAR
The following resistance should give the display shown:
Resistance Value (±5% or better) Test Output
675 Kilohm Red (Fail Lo)
825 Kilohm Green (Pass)
80 Megohm Green (Pass)
120 Megohm Red (Fail Hi)
To calibrate, simply test each resistance value shown above which
are included in the 07010 Calibration Unit. Test across the test
button and “WRIST CORD” jack for calibration of the 750 Kilohm
- 10 Megohm range. Test across the test button and “FOOT
PLATE” jack for calibration of the 750K - 100M range. Be sure
rocker switch is set correctly.
TB-2040
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© 2013 DESCO INDUSTRIES INC.
Employee Owned
Figure 11. Testing of wrist strap grounding assemblies
Figure 12. Testing foot grounding devices
4. Lighting of the green “PASS” LED indicates that the foot
ground assemblies are functioning properly.
5. If either red “FAIL LO” or red “FAIL HI” LEDs light and the
audible indicator sounds, the wearer should check the foot
grounding device immediately.
6. Repeat steps 1-3 with other foot.
Figure 13. Calibration of the Combo Tester’s 750 kilohm to
100 megohm range
Figure 14. Calibration of the Combo Tester’s 750 kilohm to
10 megohm range