This section provides overview, applications, and principles of dielectric withstand testers. Also, please take a look at the list of 9 dielectric withstand tester manufacturers and their company rankings.
Table of Contents
A dielectric withstand tester is a device that checks whether an electric product or its components are sufficiently insulated when a voltage is applied to them.
Insulation resistance testers are used to evaluate insulation performance, but voltage withstands testers differ in that they apply a voltage high enough to actually cause a dielectric breakdown.
In addition, the insulation resistance tester evaluates insulation capability quantitatively, whereas the dielectric withstand tester evaluates qualitatively whether insulation is broken or not. They are also called dielectric strength testers.
Rather than quantitatively measuring insulation performance like an insulation resistance tester, dielectric withstand testers are used to confirm whether or not insulation breakdown occurs.
Withstand voltage tests using dielectric withstand testers are included in safety standards not only in Japan but also around the world, and together with insulation performance tests using insulation resistance testers and protective continuity tests, manufacturers of electrical products are required to conduct these tests in the final process to confirm that there is no risk of electric shock or electric leakage. The following table shows the principle of voltage resistance testers.
Dielectric withstand testers apply a high voltage to an object to be tested to see if it causes dielectric breakdown.
Dielectric breakdown is when an insulator suddenly begins to conduct current at a certain time or voltage when voltage is continuously applied to it.
Dielectric withstand testers apply a very high voltage (10 to 20 times the voltage applied in normal use) to the object under test and measure whether or not a sudden increase in current due to dielectric breakdown occurs.
The basic configuration is the same as that of an insulation resistance tester, consisting of a power supply, an ammeter, and a current protection element placed upstream of the ammeter, and a switch to start and end measurement.
In general, most electrical products operate on AC power, and many problems, such as overvoltage, are also caused by AC, so it can be said that this test is suited to the actual situation. Insulation resistance testing is performed on-site during maintenance and inspections regardless of the manufacturing process, while withstanding voltage testing is performed on all products at the factory.
Before using dielectric withstand testers, an initial inspection is required. Without this initial inspection, accurate testing cannot be performed. In addition, high voltages are generated during the test, and failure to perform the inspection may injure the tester.
Since specific inspection methods vary by manufacturer, please read the instruction manual carefully before inspecting.
In general, the following items are to be checked:
”Whether the tester is grounded to the earth”
”Whether there are no cracks or damages on the exterior of the tester”
”Whether there are no cracks or damages on the measurement leads and sheaths”
In addition, the voltage that withstands the tester should be calibrated periodically. Calibration is the process of adjusting the measuring equipment to ensure that it is measuring correctly and inspecting whether the voltage withstands the tester is functioning properly. If the voltage tester has never been calibrated since its purchase, you do not know if it can be tested. It is possible to calibrate a voltage tester by yourself, but it must be done by someone with sufficient knowledge and skills because high voltages may flow through the tester. Therefore, it is generally recommended to have a professional manufacturer calibrate dielectric withstand testers once every six months to several years.
Dielectric withstand testers are also available for rental. However, when selecting equipment, how much applied voltage is needed? Will you be testing DC or AC? At the very least, it is necessary to consider the following questions.
The dielectric withstand testerss available for rent are available in a variety of types with different functions. Types that can display voltmeters and ammeters digitally can reduce the risk of misreading measurements. Some models are also capable of insulation resistance testing, so if you want to perform insulation resistance testing, one unit is all you need. Renting a high-performance model that you do not need will result in unnecessary costs, so make your selection by carefully comparing it with your actual usage.
Rental fees for voltage resistance testers range from 20,000 to 100,000 yen per month, depending on the functionality.
*Including some distributors, etc.
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Ranking as of January 2023 in United States
Derivation MethodRank | Company | Click Share |
---|---|---|
1 | GW Instek | 100% |
Ranking as of January 2023 Globally
Derivation MethodRank | Company | Click Share |
---|---|---|
1 | Chroma | 33.3% |
2 | Finero | 33.3% |
3 | GW Instek | 33.3% |
Derivation Method
The ranking is calculated based on the click share within the dielectric withstand tester page as of January 2023. Click share is defined as the total number of clicks for all companies during the period divided by the number of clicks for each company.Number of Employees
Newly Established Company
Company with a History
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