Proving Units

In Stock

Martindale PD240 pocket Sized Proving Unit for use with Voltage Indicators

(1)

£74.40 £62.00
- Maximum output current of 2mA
- Maximum output voltage of 240V
- Compact body made from flame-retardant ABS for safety
62 Reward Points

Price Match Guarantee

MARPD240

View Product
Martindale PD230SRD – 230V AC/DC Proving Unit with 3 Ranges

(no reviews)

£100.80 £84.00
- 3 ranges
- Switchable AC / DC output mode
- Suitable for use with voltage indicators up to 230V
84 Reward Points

Price Match Guarantee

MARPD230SRD

View Product
5 In Stock

Martindale PD440S 440V Proving Unit

(no reviews)

£106.80 £89.00
- Auto Power Off
- Lightweight, compact, and rugged
- Long battery life
- Low battery indicator
89 Reward Points

Price Match Guarantee

MARPD440S

View Product
In Stock

Martindale PD690S 690V Proving Unit

(no reviews)

£112.80 £94.00
- Single voltage output: 690V AC
- Applies full voltage upon contact
- Auto Power Off function
- Long battery life
94 Reward Points

Price Match Guarantee

MARPD690S

View Product
Only 1 In Stock

Martindale PD440SX 440V Proving Unit with CALCHECK

(no reviews)

£123.60 £103.00
- Stepped voltages
- CALCHECK
- Auto Power Off function
- Low battery indicator
103 Reward Points

Price Match Guarantee

MARPD440SX

View Product
3 In Stock

Martindale PD690SX 690V Proving Unit with CALCHECK

(no reviews)

£126.00 £105.00
- CALCHECK
- Low battery indicator
- Long battery life
- Auto Power Off function
105 Reward Points

Price Match Guarantee

MARPD690SX

View Product
Lead Time: 1-2 Weeks

Martindale PD440SRD – 440V AC/DC Proving Unit with 4 Ranges

(no reviews)

£136.80 £114.00
- 4 ranges
- Switchable AC / DC output mode
- Suitable for use with voltage indicators up to 440V
114 Reward Points

Price Match Guarantee

MARPD440SRD

View Product
Martindale PD440SRDX – 440V AC/DC Proving Unit with 4 Ranges & CALCHECK

(no reviews)

£148.80 £124.00
- CALCHECK
- 4 ranges
- Compatible with S-series magnetic hanger
124 Reward Points

Price Match Guarantee

MARPD440SRDX

View Product
Lead Time: 1-6 Days

Martindale PD690SRD – 690V AC/DC Proving Unit with 5 Ranges

(no reviews)

£148.80 £124.00
- 5 ranges
- Switchable AC / DC output mode
- Suitable for use with voltage indicators up to 690V
124 Reward Points

Price Match Guarantee

MARPD690SRD

View Product
Lead Time: 1-6 Days

Martindale PD690S-C 690V AC Proving Unit & TC71 Carry Case

(no reviews)

£150.00 £125.00
- Low-profile, durable proving unit
- 690V test voltage
- Heavy denier nylon case with a shoulder strap and clear front pocket
125 Reward Points

Price Match Guarantee

MARPD690S-C

View Product
Only 1 In Stock

Martindale VIPD138-S Voltage Indicator & Proving Unit Kit

(no reviews)

£179.40 £149.50
- PD440S: 440V industry-leading proving unit
- VI13800 Voltage tester range: 50V to 600V AC/DC
- TC71 Combination Carry Case
149 Reward Points

Price Match Guarantee

MARVIPD138-S

View Product
Lead Time: 1-2 Weeks

Martindale VIPD150-S Voltage Indicator & Proving Unit Kit

(no reviews)

£210.00 £175.00
- Industry-leading 690V PD690S Proving Unit
- VI15000 Voltage Indicator range: 50 to 1000V AC/DC
- Use the PD690S Proving Unit through the TC71 Carry Case
175 Reward Points

Price Match Guarantee

MARVIPD150-S

View Product
Only 1 In Stock

Martindale Drummond MTL10PD Test Lamp and Proving Device - Tool Kit

(1)

£211.14 £175.95
- Proving unit checks accuracy up to 440V
- 500V AC, 750V DC voltage
- LED light up display
175 Reward Points

Price Match Guarantee

DRUMTL10PD

View Product
Lead Time: 1-2 Weeks

Martindale MTL15PD Drummond Test Lamp and Proving Unit Kit

(no reviews)

£238.80 £199.00
- Includes Martindale’s MTL15 Test Lamp, PD690 Proving Unit and TC69 Carry Case
- Test lamp can be used to prove that high-power equipment is dead prior to commencing maintenance and repair work
- PD690 Proving Unit can be used to verify the functionality of the test lamp
199 Reward Points

Price Match Guarantee

MARMTL15/PD

View Product
In Stock

Martindale VIPDLOK138-S Voltage Indicator, Proving Unit & Lockout Kit

(no reviews)

£250.80 £209.00
- VI13800 Voltage Tester: 50-600V AC/DC
- 440V PDS440S Proving Unit that can be used through the TC71 Case
- LOKKIT1 12-Piece Lockout Kit
209 Reward Points

Price Match Guarantee

MARVIPDLOK138-S

View Product
Only 1 In Stock

Martindale VIPDLOK150-S Voltage Indicator, Proving Unit, & Lockout Kit

(no reviews)

£286.80 £239.00
- Industry-leading 690V PD690S Proving Unit can be used through the TC71 Case
- VI15000 Voltage Indicator range: 50 to 1000V AC/DC
- 12-piece LOKKIT1 Lockout Kit
239 Reward Points

Price Match Guarantee

MARVIPDLOK150-S

View Product
Only 1 In Stock

Free UK Delivery

Martindale VIPDLOKPRO138-S Voltage Indicator, Proving Unit & Pro Lockout Kit

(no reviews)

£322.80 £269.00
- VI13800 Voltage Tester: 50-600V AC/DC
- 440V PDS440S Proving Unit that can be used through the TC71 Case
- LOKKITPRO 17-Piece Lockout Kit
269 Reward Points

Price Match Guarantee

MARVIPDLOKPRO138-S

View Product
Only 1 In Stock

Free UK Delivery

Martindale VIPDLOKPRO150-S Voltage Indicator, Proving Unit, & Pro Lockout Kit

(no reviews)

£346.80 £289.00
- Industry-leading 690V PD690S Proving Unit can be used through the TC71 Case
- VI15000 Voltage Indicator range: 50 to 1000V AC/DC
- 17-piece LOKKITPRO Lockout Kit
289 Reward Points

Price Match Guarantee

MARVIPDLOKPRO150-S

View Product

Shop By:

62.00 289.00

About Proving Units

Proving units are portable, lightweight calibration tools that are designed for use with two-pole voltage testers. The function of a proving unit is to evaluate that the internal components of the voltage tester are working correctly and that measurement accuracy is maintained.

Although regular, formal calibration is still a priority, using a proving unit in combination with a two-pole voltage tester is an ideal way to ensure measurement accuracy is maintained in the period between official calibration procedures. Most manufacturers recommend that a proving unit is used both before and after testing using a voltage tester; this way, damage to the machine during transportation can be detected before testing, or damage to the machine during the actual testing procedure can be detected afterward.

Proving units come in many different forms to accommodate the vast voltage range spectrum that can be applied to two-pole testers. Some proving units might be designed for measuring low voltage testers, while others may be designed for higher voltage. Some may also be suitable for both low and high-voltage testers, measuring across the entire spectrum. A common function found on these units is ramp voltage. The proving unit applies several different voltages to the two-pole voltage tester that is inserted into ports on the proving unit and the device measures whether everything is working correctly with the applied voltage. The indicators are usually expressed via the use of LED lights and if everything is correct the LED light indicators should tell you that this is the case.

Stepped voltages again vary depending on the proving unit being used.

Using a proving unit to maintain accuracy is particularly important as frequent usage of a tester can result in the compromise of measurement accuracy. Other factors such as knocks and bumps, dust, water, and other forms of natural contaminants can also affect the accuracy of a tester over time and if these inaccuracies go unnoticed it can make the tester unsafe and also produce incorrect readings when used on a system.

Our range of proving units come from many different manufacturers, including Kewtech, Martindale, Megger, Seaward, and Socket and See. As mentioned earlier their capabilities vary from tester to tester, so knowing which unit you need before making a purchase is highly recommended. If you're confused about which unit you need we're more than happy to help you make a decision - get in touch and we'll help you out choosing the right proving unit for use with your voltage tester.