Megger BM11, BM21 and BM25
5 kV Insulation Testers,
See: MIT515 or MIT525

  • Spot Tests and Diagnostic insulation tests
  • Simplicity and Ease of Use
  • User safety features
  • Unique rugged casing
  • Analog and Analog/Digital Displays
  • Wide range of test voltages
  • Automated Testing (BM25 Only)

BM25 Shown

Product Information
Datasheet 133 KB
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The Megger® BM11 series of 5 kV Insulation Testers provides a choice of features to suit all applications and budgets.

The traditional BM11 instrument became the industry-standard 5 kV tester. It is battery-powered, housed in a rugged case and has a large, simple white-on-black scale.

The series has been extended with three analog/digital instruments; the BM11D, BM21 and BM25. These instruments show results and test options on a large, clear analog/digital scale for both practicality and precision. A built-in timer makes both spot tests and PI testing easier to carry out.

They are powered by a built-in rechargeable lead-acid battery which can be charged directly from any supply from 95 V to 265 V. All testers incorporate a guard terminal to allow surface leakage to be removed.

Pre-set standard test voltages at 500 V, 1000 V, 2500 V and 5000 V are supplemented on the BM21 and BM25 unit switch a variable test voltage in 25 V steps. These top of the range units also allow measurement of resistance to 5 TΩ,leakage current to 0,01 nA and can display capacitance at the end of a test to 10 µF.

The BM25 extends the diagnostic testing capability of the range by performing automatic Polarization Index, Step-Voltage and Dielectric Discharge tests as well as providing an optically isolated RS232 port for downloading results during a test.

Test Voltage (VDC) 500
25 - 5000 (25V steps)
Resistance Range
10 kΩ - 50 GΩ (digital)
10 kΩ - 100 GΩ (digital)
10 kΩ - 250 GΩ (digital)
10 kΩ - 500 GΩ (digital)
100 kΩ - 1 TΩ (analog)
10 kΩ - 500 GΩ (digital)
10 kΩ - 1 TΩ (digital)
10 kΩ - 2.5 TΩ (digital)
10 kΩ - 5 TΩ (digital)
100 kΩ - 1 TΩ (analog)
Voltage Range 50-1000V (DC or AC) 50-1000V (DC or AC);
0-5000 VDC (when Testing)
Leakage Current Range None 0.01 nA - 999 µA
Capacitance Range None 0.0(1) 10 µA
Display Digital/Analog Digital/Analog Automated Testing
Power Built-in Charger,95 to 265 VAC, 50/60 Hz (Lead Acid)
Ordering Information
Model Description Buy Online Price
BM11 Megger BM11, Analog 5 kV Megger Insulation Tester; 500, 1000, 2500, 5000 V; 100 GOhms  Discontinued
See: MIT515
BM11D Megger BM11D 5 KV Digital/Analog Insulation Tester (218651) Discontinued
See: MIT515
BM21 Megger BM21 5000 Volt Insulation Tester (218621)  Discontinued
See: MIT525
BM25 Megger BM25, 5 KV Digital/Analog Insulation Tester  Discontinued
See: MIT525
Included Accessories

BM11D, BM21, and BM25 Accessories

  • (1) High Voltage Test Lead set
  • (1) Mains Supply lead for charging
  • (1) Accessory pouch
  • (1) PC Connector lead
  • (1) BM25 download disk (BM25 only)
  • (1) Test record Card Set (5 in pack)
  • (1) User Guide