0 Cookie Img

High Voltage Sphere Gap Measurement

High Voltage Sphere Gap Measurement
High Voltage Sphere Gap Measurement
Product Code : AE-02
Product Description

SPHERE GAP (With 60 mm sphere)

Technical details of the instrument are as follows:

2 No Sphere 60 mm (Adjustable)

1 No Nylon rod

1 No MS Fabricated box

1 No Rotation wheel (Hand operated)

Procedure (Usage):

1. Connect the test gap to the transformer.

2. Adjust the gap distance to an initial value of 10mm.

3. Close the circuit breaker.

4. Slowly raise the till faint hissing audible sound is heard. Note the reading on the
Analog Multimeter and actual value from the calibration chart provided. This is the
beginning of corona. Hence, the Corona Inception Voltage.

5. Raise the Voltage further till such time there is a faint visible glow at the high
voltage electrode. This is the Visible Corona Inception level. Note the value.

6. Then slowly reduce voltage further till such time the hissing sound subside i.e., dies
down or becomes extinct. Note this value as Corona Extinction Voltage.

7. Once again raises the voltage till such time there is a Break Down. Note this value
as break down Voltage.

8. Reduce the voltage completely and open the circuit breaker.

9. Increase the gap distance by 5mm and repeat steps 3 to 8.

10. Repeat step 9 for 6 (six) different gap distances.

11. Repeat the experiment for test Gap.

12. Correct the observed values for standard atmospheric conditions and plot the gap
distance Vs Breakdown voltage for each gap.


Sphere Gap Assembly is used for measurement of A.C. / D.C., or impulse voltages. It can be of vertical or horizontal type depending on requirements. Micrometer scale is provided to read the gap up to the accuracy of 0.1mm.

Each sphere gap assembly comes with a series water resistor for the protection of spheres against pitting, All the metal parts are hard chrome plated  and insulating support is painted with anti-tracking paints.

Sphere gap assemblies are available in 50mm, 62.5mm, 100mm, 150mm, 250mm and 500mm diameter ratings.

Contact Us

Shop No.: 1 & 2, Uma Sharnam, Near Aryan city, Vandemataram, Gota, Ahmedabad, Gujarat, 382481, India