DESCO WEST
- 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178 • Fax (909) 627-7449
DESCO EAST
- One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Fax (781) 575-0172 • Website:
TB-3041
Page 5 of 6
© 2009 DESCO INDUSTRIES, INC.
Employee Owned
NEGATIVE DISCHARGE TIME MEASUREMENTS
To provide a NEGATIVE voltage output, touch the plate
located underneath the Charger, and press the switch
downward at the same time. Momentarily touch the
Charger’s output terminal to the conductive plate
attached to the Field Meter. The meter reads
approximately -1.10 kV. By using a stop watch or other
timing device, determine the time needed for the
voltages to decrease from -1.10 kV to -0.10 kV. This is
the negative discharge time.
IMPORTANT:
A ground path must be provided between
the touch plate of the Charger and the ground reference
of the Field Meter. This is normally provided by holding
the Charger in one hand and the Field Meter with
Conductive Plate in the other.
The battery in the Charger should be replaced annually
or when it is unable to provide approximately ±1100V.
CLEANING
It is important to keep the insulators on the adapter plate
clean and free of contaminates that may cause surface
leakage. To test the performance of the adapter plate,
charge the plate and note the discharge rate in a nonion
-
ized area. The self discharge rate to 10% of original
voltage should not be less than five minutes.
The area around the aperture of the Digital Static Field
Meter must be kept clean to ensure accurate, drift-free
readings. Never touch the aperture with anything. To
remove dust or other particulate matter, use low-
pressure instrument-grade air. To remove more severe
contamination, spray or flush with the smallest practical
amount of clean technical-grade of isopropyl alcohol.
Then allow the instrument to air dry for several hours.
Specifications
DIGITAL STATIC FIELD METER
Measurement Range (switch selectable)
Low Range:
0 to ±1.99 kV / inch
High Range:
0 to ±19.99 kV / inch
Measurement Accuracy
Voltage Monitor Output: > ±5% of reading ±10 mV
Voltage Display:
> ±5% of reading ±2 counts
Measurement Stability
±10 counts
Automatic Shutoff
Unit will shut off after 20 minutes after last switch activity
Power Requirements
One (1) 9V alkaline battery
Operating Time
Greater than 50 hours, with new battery at 21°C
continuous usage
Operating Conditions
Temperature:
10-30°C
Relative Humidity:
Up to 80%, non-condensing
Altitude:
Up to 2,000 meters
Dimensions
0.94" H x 2.75" W x 4.94" L
(23.9mm H x 69.9mm W x 125.5mm L)
Weight (with battery)
4.9 oz
(153 g)
Voltage Monitor Connection
2.5mm audio jack
CE Certified
Figure 8. Taking decay measurements
Maintenance
The Digital Static Field Meter is factory calibrated and no
maintenance is required. If for any reason you believe
the Meter is not working correctly, please contact Desco
Customer Service. CAUTION - There are no user
serviceable parts. Any unauthorized service will void the
warranty and result in additional repair charges.
Note:
This Meter is a precision instrument and should
not be subjected to dropping as that would void the
warranty.
BATTERY REPLACEMENT
The Digital Static Field Meter operates from a standard
9 VDC alkaline battery. Battery life is in excess of 50
hours under normal use. When the battery voltage
drops below 6.5 V, “BAT” will appear on the display. To
change the battery, slide the battery cover down at the
back of the Meter and remove the battery from the
battery clip. Replace the battery with a fresh one and
reinstall the battery cover. The battery should be
removed from the Meter if its is to be stored for an
extended period of time.