Fluke 80K-40 User Manual

Maintenance

Performance Test

Verify the probe accuracy by measuring a 25 kV dc ±0.25% voltage source. When used with a compatible dc voltmeter, the probe should measure the source with ±1% accuracy. No calibration adjustments are provided.

80K-40

High Voltage Probe

Cleaning

Use a soft cloth dampened in distilled water to clean the 80K-40. Never use solvents or abrasive cleaners. Make sure the 80K-40 is dry before reuse.

LIMITED WARRANTY & LIMITATION OF LIABILITY

Each Fluke product is warrant ed to be free from defects in material and workmanship under normal use and servi ce. The warranty period is one year and begins on the date of shipment. Parts, product repairs and services are warranted for 90 days. This warranty extends onl y to the original buyer or end-user customer of a Fluke authorized reseller, and does not apply to fuses, disposable batteries or to any product which, in Fluke’s opinion, has been misused, al tered, neglected or damaged by accident or abnormal conditi ons of operation or handling. Fluke warrants that software will operate substantially in accordance with its func t i onal specifications for 90 days and that it has been properly recorded on nondefective media. Fluke does not warrant that software will be error free or operate without interruption.

Fluke authorized resellers shall extend this warranty on new and unused products to end-user cust om ers only but have no authority t o extend a greater or different warranty on behalf of Fl uke. Warranty support is available if product is purc hased through a Fluke authorized sales outlet or Buyer has paid the applicable international price. Fluke reserves the right to invoice Buyer for importation costs of repai r/replacement parts when product purchased in one country i s submitted for repair in another country.

Fluke’s warranty obligation is limited, at Fluke’s option, to ref und of the purchase price, free of charge repai r, or replacement of a defective product which is returned to a Fluke authorized service center within the warranty period.

To obtain warranty service, contact your nearest Fluke authorized service center or send the product, with a description of the difficulty, postage and insurance prepaid (FOB Destinati on), to the nearest Fluke authoriz ed service center. Fluk e assumes no risk for damage i n t ransit. Following warranty repair, the product will be returned to Buyer, transportation prepaid (FOB Destination). If Fl uke determines that the fai l ure was caused by misuse, al t eration, accident or abnormal condi tion of operation or handling, Fluke will provide an estimate of repair costs and obtain authorization before commencing the work. Following repair, the product will be returned to the Buyer transportation prepaid and the Buyer will be billed for the repair and return transport at i on charges (FOB Shipping Point).

THIS WARRANTY IS BUYER’S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. FLUKE SHALL NOT BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSSES, INCLUDING LOSS OF DATA, WHE T HE R ARISING FROM BREACH OF WARRANTY OR BASED ON CONTRACT, TORT, RELIANCE OR ANY OTHER THEORY.

Since some countries or states do not allow limitation of the term of an implied warranty, or excl usion or limitation of inc i dent al or consequential damages, the limitat i ons and exclusions of this warranty may not apply to every buyer. If any prov i sion of this Warranty is hel d i nvalid or unenforceable by a court of competent juris diction, such holding will not affect the validity or enforceability of any other provision.

Fluke Corporation Fluke Europe B.V. P.O. Box 9090 P.O. Box 1186 Everett, WA 98206-9090 5602 BD Eindhoven U.S.A. The Netherlands

Instruction Sheet

Introduction

The Model 80K-40 is a high voltage accessory probe designed to extend the voltage measuring capability of an ac/dc voltmeter up to 40,000 volts Overvoltage Category I. This means the probe can only be used to make measurements on energy limited circuits within equipment. Examples include high voltage within televisions or photo copy machines. DO NOT use this probe to measure high voltages on power distribution systems. The probe is a precision 1000:1 voltage divider formed by two matched resistors. The unusually high input impedance offered by these resistors minimizes circuit loading and thereby, optimizes measurement accuracy. A special plastic body houses the divider and provides the user with isolation and protection from the voltage being measured.

Specifications

The 80K-40 will achieve rated accuracy when used with a voltmeter (ac or dc) having an input impedance of 10 MΩ ±1.0%.* Specifications for the probe are as follows:

†Voltage Range: 1 kV to 40 kV dc or peak ac, 28 kV rms ac Input Resistance: 1000 MΩ Division Ratio: 1000: 1 (1000X attenuator) Accuracy DC:

20 kV to 35 kV: ±1% at 20°C to 30°C; add 1% at 10°C

<20°C and >30°C to 45°C. (For total measurement accuracy add accuracy specification of voltmeter being used.)

0 kV to <20 kV and >35 kV to 40 kV: ±2%. Accuracy AC: 60 Hz, ±5%. Safety: Meets IEC 1010-2-031:1993, Type B, 40 kV dc or, peak

ac, 28 kV rms ac, Overvoltage Category I (voltages derived from limited energy transformer).

* The input impedance of Autoranging Fluke handheld digital multimeters varies as a function of range. The only range that deviates significantly from 10 MΩ is the 3V (Models 21, 23, 25, 27, 70, 73, 75, 77) or 4V (Models 10, 11, 12, 29, 79, 83, 85, 86, 87, 88) range where the impedance is 11.11 MΩ. To enhance the measurement accuracy when using this range, apply a correction factor of 0.99, i.e. multiply the displayed reading by .99.

† This probe is intended for low energy applications such as CRT and similar circuits. Above 2000 meters altitude, and up to 5000 meters, derate linearly the working voltage from 40 kV peak to 28 kV peak, and derate linearly the transient overvoltage from 80 kV peak to 57 kV peak. Transient overvoltage refers to micro-second duration impulses caused by lightning or load switching. See International Electrotechnical Commission Publication 664-1980, Clause 3.9 Table II, and Appendix A.

Measurement Considerations

Before attempting to use the 80K-40, the following paragraphs should be read and understood. Particular attention should be given to Operator Safety.

5/94

PN 481978 January 1978, Rev.9, 3/97

Operator Safety

Indicates the operator must refer to an explanation in this manual.

Indicates terminals at which lethal voltages may exist.

Circuit Loading

The 80K-40 represents a 1000 MΩ load to the circuit being measured, or 1 µA per 1 kV. Table 1 shows the circuit loading and input/output characteristics of the probe over its measurement range.

Warning

• To avoid damage or electric shock:

• Use within ratings and under dry (no

condensation) conditions.

• The 80K-40 user should be familiar with, and

exercise, all possible high voltage safety practices.

• When making a measurement, never make body

contact with the probe tip or the red portion of the probe. Always hold the probe by its black handle.

• Before making a measurement, make sure that

the tab side of the output connector is connected to the voltmeter’s low input terminal.

• The clip lead must be attached to earth ground.

Voltmeter Compatibility

Accuracy of the meter is not included in the accuracy of the probe, and must be added to the probe accuracy to determine system accuracy.

The 80K-40 is mechanically compatible with any ac or dc voltmeter or multimeter capable of accepting a standard spaced,

0.75" (19mm) double, banana plug, having standard, .160" (4mm) plugs.

The 80K-40 probe is electrically compatible with any ac or dc voltmeter or multimeter that has an input impedance of 10 MΩ ±1%. Voltmeters or multimeters with other input impedances require the use of an external shunt or a correction factor to obtain an accurate measurement. Higher impedance voltmeters or multimeters should be equipped with a shunt, and lower impedance voltmeters or multimeters should be assigned correction factors. Applicable formulas follow:

a. The following formula is used to determine the value of an

external shunt resistor (meter impedance >10 MΩ):

Rm x 10

Rm 10=−

Where: Rs = Shunt resistance in MΩ

Example: If RM = 20 MΩ,

b. Use the following formula to calculate a correction factor

(meter impedance <10 MΩ):

Where: Cf=Correctionfactor (multiplier for meter reading)

Example: If Rm = 1 MΩ,

Therefore: A meter reading of 0.526 volts represents an input of: 0.526 x 1.901 = 1 or 1 kV.

Rm = Voltmeter input impedance in MΩ (>10 MΩ)

20 x 10 20 10

1.11 + Rm

1.11 x Rm

Rm = Voltmeter input impedance in MΩ

1.11 + 1

1.11 x 1

200

=2.0M=

Ω

=1.901=

2.11

1.11

−

Table 1. 80K-40 Circuit Loading and Input/Output Characteristics

Input Voltage Loading Current Output Voltage

10V

100V

1 kV 10 kV 20 kV 30 kV 40 kV

10 nA

100 nA

1µA 10 µA 20 µA 30 µA 40 µA

10 mV

100 mV

1V 10V 20V 30V 40V

Operation

Use the following procedure to operate the 80K-40:

1. Select and energize a compatible voltmeter.

2. Equip the voltmeter with a suitable shunt, if required.

3. Select an appropriate voltage range (1 volt reading per 1000 volt input. See Table 1).

4. Connect the probe’s output leads to the voltmeter input terminals.

5. Connect the probe’s clip lead to ground. See OPERATOR SAFETY.

6. Connect probe tip to circuit being measured and observe voltmeter reading. Apply correction factor to reading when necessary.

Theory Of Operation

The 80K-40 High Voltage probe, is designed to extend the voltage measurement range of an ac/dc voltmeter up to 40,000 volts. Electrically, the probe is a passive attenuator as shown in Figure 1. Its high input impedance (1000 MΩ), as well as its accuracy and stability characteristics are achieved through the use of special thick film resistors. When the probe is connected to a voltmeter with a 10 MΩ input resistance the probe becomes an accurate 1000:1 divider. Notice that the divider depends upon a ground lead to complete the low side of the circuit path. Therefore, this connection must always be secure before attempting a voltage measurement. Otherwise, instrument damage or a shock hazard will result.

80K-40 DC Voltmeter

Probe Tip

Replacement Resistor Kit

PN 939335

Ground

Lead

Figure 1. 80K-40 Simplified Circuit Diagram

10MΩ