TECHNICAL BULLETIN TB-3040 Digital Static Field Meter Made in the Operation and Maintenance United States of America When any object becomes electrostatically charged, there is an electrostatic field associated with that charge. If an ESDS (ESD sensitive) device is placed in that electrostatic field, a voltage may be induced on the device. If the device is then momentarily grounded, a transfer of charge from the device occurs as a CDM (Charged Device Model) event. If the device is removed from the region of the electrostatic field and grounded again, a second CDM event will occur as charge (of opposite polarity from the first event) is transferred from the device. (Handbook ESD TR20.20 section 2.7.5 Field Induced Discharges) All nonessential insulators such as coffee cups, food wrappers and personal items shall be removed from the EPA. The ESD program shall include a plan for handling process-required insulators in order to mitigate field-induced CDM damage. If the field measured on the process required insulator is greater than 2000 volts/inch and the process required insulator is less than 30 cm (12 inches) from the ESDS item, steps shall be taken to either: A) Separate the required insulator from the ESDS item by a distance of greater than 30 cm (12 inches) or B) Use ionization or other charge mitigating techniques Figure 1. Desco 19492 Digital Static Field Meter to neutralize the charge. Description If the field measured on the process required insulator is greater than 125 volts/inch and the process required The Desco Digital Static Field Meter indicates surface insulator is less than 2.5 cm (1 inch) from the ESDS voltage and polarity on objects. The meter can measure item, steps shall be taken to either: ranges of 0 to 1.999 kV or 0 to 19.99 kV at a distance of 1 inch with an accuracy of 5% of the displayed A) Separate the required insulator from the ESDS item value. The automatic zero button allows adjustment to by a distance of greater than 2.5 cm (1 inch) or zero with no screws or dials to turn. The hold button allows the user to freeze a displayed measurement B) Use ionization or other charge mitigating techniques for evaluation. A LED range finder helps the operator to to neutralize the charge. place the meter at the correct distance from the surface NOTE: The accurate measurement of electrostatic fields being measured. The meter will automatically turn off requires that the person making the measurement is after 20 minutes to conserve battery power (9V). The familiar with the operation of the measuring equipment. Digital Static Field Meter is calibrated with accepted Most hand held meters require that the reading be taken procedures and standards traceable to the National at a fixed distance from the object. They also normally Institute of Standards and Technology. specify that the object has a minimum dimension of fixed size in order to obtain an accurate reading. (ANSI/ ESD S20.20-2014 section 8.3.1 Insulators) 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 2018 DESCO INDUSTRIES, INC. TB-3040 Page 1 of 5 April 2018 Employee OwnedD. HOLD Button: Press to freeze the reading on the Packaging display. Press again to return to normal measurement 1 Digital Static Field Meter operation. 1 9V Alkaline Battery 1 Certificate of Calibration E. Battery Cover: Slide the cover down to open the 9V battery compartment. Features and Components Operation Note: The Digital Static Field Meter is built in a conductive case. The instrument senses the difference in potential between the case (and the person holding the case / ground connection) and the surface under test. Ensure that the person using the instrument is wearing a wrist strap and grounded to achieve more accurate measurements. BATTERY CHECK C The battery should be replaced when BAT is indicated A D on the display. Always replace the battery with a 9V alkaline or equivalent battery in order to remain CE compliant. B ZERO THE METER Turn the meter on by pressing the POWER button. Press the RANGE / ZERO button to set the meter to FRONT VIEW the 2 kV (3 decimal places) range. Point the top of the Meter approximately 1 inch away from a grounded metal surface. Use the red LED range guide. The Meter is properly positioned when the projected red bullseyes are centered on top of each other. Press and hold the RANGE / ZERO button until the meter displays .000. MAKING A MEASUREMENT Place the meter 1 inch from the object to be measured. This distance is measured from the front edge of the meter case to the surface of the object. The meter now displays a reading (from 0 to .200 or 2.00) of the electrostatic field in kilovolts per inch. Note: The red ranging lights are provided to help place the meter at the correct distance from the object. The E lights are set to produce a concentric red bullseye pattern on a flat opaque surface 1 inch from the front edge of the meter. This can be practiced by aiming the meter at a sheet of white paper. BACK VIEW The display will indicate 1 or -1 when the meter is over-ranged. Change the range of the unit if necessary. Figure 2. Digital Static Field Meter features and If the measurement exceeds 20 kV, move the meter components farther away from the object and multiply the reading by the distance (in inches) away from the object being A. POWER Button: Press to turn the unit ON and OFF. measured. The measurement accuracy is dependent on a stable ground reference and the 1 inch measuring B. RANGE / ZERO Button: Press to select the distance. It is also dependent on the aspect ratio, measurement range. Press and hold to zero the meter. relating the size of the object to be measured to the C. Analog Output Jack: A low-voltage signal of the measurement distance. measured voltage is provided at this output. The voltage is 1/1000th (2 kV range) or 1/10,000 (20 kV range) of the measured voltage. 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 2018 DESCO INDUSTRIES, INC. TB-3040 Page 2 of 5 Employee Owned