Martindale CM57 AC TRMS Clamp Meter

SKU: MAT/CM57
MPN: MARCM57
  • Ideal for HVAC testing and fault finding
  • True RMS readings for reliable AC checks
  • Compact clamp for restricted access areas
  • Measures current, voltage and capacitance

£69.00 (ex VAT)

£82.80 (inc VAT)

Earn 69 points

Usually ships In 3 to 5 working days

Why buy from Test4Less?

  • Ideal for HVAC testing and fault finding
  • True RMS readings for reliable AC checks
  • Compact clamp for restricted access areas
  • Measures current, voltage and capacitance
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£69.00 (ex VAT)

£82.80 (inc VAT)

Earn 69 points

Usually ships In 3 to 5 working days

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Martindale CM57 AC TRMS Clamp Meter

The Martindale CM57 AC TRMS Clamp Meter is a small instrument designed for electrical testing and HVAC work. It measures AC current without breaking the circuit and provides resolution down to 10 mA. Its True RMS measurement supports reliable readings when checking AC systems.

Alongside AC current, the meter measures AC and DC voltage, resistance, capacitance and frequency. A built-in non-contact voltage sensor provides a quick way to detect live voltage through the clamp jaw. The display light and hold function also help when working in dark or tight locations.

Its compact build makes the Martindale CM57 AC TRMS Clamp Meter easier to position where access is limited. Its oval jaw fits around cables up to 25 mm in width or 35 × 15 mm, while the control wheel supports one-handed use. Auto-ranging, automatic power-off and a low-battery warning make regular testing easier and help users manage the instrument during daily work.

 

Key Benefits
  • Measures AC current without breaking the circuit.
  • True RMS operation supports dependable AC measurements.
  • Auto-ranging reduces the need for manual range selection.
  • A thumbwheel allows convenient single-handed operation.
  • The compact elliptical jaw reaches restricted locations.
  • A backlit display improves visibility in low-light areas.
  • The hold function keeps a useful reading on the display.
  • Non-contact detection helps identify the presence of live voltage.
  • Automatic power-off helps preserve battery life between tests.
  • Capacitance and frequency modes support wider fault-finding tasks.

 

Common Applications

Martindale CM57 AC TRMS Clamp Meter is suitable for a range of testing, maintenance and inspection tasks, including:

  • Measuring AC current in HVAC equipment.
  • Checking AC and DC voltage levels.
  • Testing resistance and circuit continuity.
  • Measuring component capacitance.
  • Checking current and voltage frequency.
  • Detecting the presence of live voltage without contact.
  • Electrical fault finding in areas with restricted access.
  • Routine testing by electricians and service teams.

 

Why Choose This Model?

The CM57 adds True RMS measurement, frequency, capacitance, non-contact voltage detection and a display backlight compared with the CM55. It also accepts a larger conductor than the CM69, while retaining a CAT III 600 V safety category.

pdf
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Martindale CM57 AC TRMS Clamp Meter

The Martindale CM57 AC TRMS Clamp Meter is a pocket-sized instrument designed for electrical testing and HVAC work. It measures AC current without requiring the circuit to be broken and provides resolution down to 10 mA. Its True RMS measurement supports dependable readings when checking AC systems.

Alongside AC current, the meter measures AC and DC voltage, resistance, continuity, capacitance and frequency. A built-in non-contact voltage detector adds a quick way to detect live voltage through the clamp jaw. The display backlight and hold function also help when working in dim or restricted locations.

Compact construction makes the Martindale CM57 AC TRMS Clamp Meter easier to position where access is limited. Its elliptical jaw accepts conductors up to 25 mm in diameter or 35 × 15 mm, while the thumbwheel supports single-handed control. Auto-ranging, automatic power-off and a low-battery indicator simplify regular testing and help users manage the instrument during day-to-day work.

 

Key Benefits
  • Measures AC current without breaking the circuit.
  • True RMS operation supports dependable AC measurements.
  • Auto-ranging reduces the need for manual range selection.
  • A thumbwheel allows convenient single-handed operation.
  • The compact elliptical jaw reaches restricted locations.
  • A backlit display improves visibility in low-light areas.
  • The hold function keeps a useful reading on the display.
  • Non-contact detection helps identify the presence of live voltage.
  • Automatic power-off helps preserve battery life between tests.
  • Capacitance and frequency modes support wider fault-finding tasks.

 

Common Applications

Martindale CM57 AC TRMS Clamp Meter is suitable for a range of testing, maintenance and inspection tasks, including:

  • Measuring AC current in HVAC equipment.
  • Checking AC and DC voltage levels.
  • Testing resistance and circuit continuity.
  • Measuring component capacitance.
  • Checking current and voltage frequency.
  • Detecting the presence of live voltage without contact.
  • Electrical fault finding in areas with restricted access.
  • Routine testing by electricians and service teams.

 

Why Choose This Model?

The CM57 adds True RMS measurement, frequency, capacitance, non-contact voltage detection and a display backlight compared with the CM55. It also accepts a larger conductor than the CM69, while retaining a CAT III 600 V safety category.

Product Comparison
Feature CM55 CM57 CM69
AC current Yes Yes Yes
AC/DC voltage Yes Yes Yes
Resistance Yes Yes Yes
True RMS No Yes Yes
Frequency No Yes No
Capacitance No Yes No
Non-contact voltage detection No Yes No
Backlight No Yes Yes
Maximum conductor size 25 mm diameter or 35 × 15 mm 25 mm diameter or 35 × 15 mm 20 mm diameter
Notable function Basic AC clamp measurement Frequency, capacitance and live-voltage detection Low-pass filter, peak and 0.001 mA resolution
Safety category CAT III 600 V CAT III 600 V CAT III 600 V, CAT IV 300 V

 

General Specifications
Specification Details
Product type Pocket-sized True RMS AC clamp meter
Measurement functions AC current, AC/DC voltage, resistance, continuity, capacitance and frequency
Reading method True RMS
Range selection Auto-ranging
Display backlight Yes
Hold function Yes
Non-contact voltage detector Yes, detection through the jaw
Automatic power-off Yes
Battery indicator Low-battery indication
Safety category CAT III 600 V

 

Measurement and Accuracy Specifications
Specification Details
AC current ranges 60.00 A and 600.0 A
Minimum AC current resolution 10 mA
AC voltage ranges 6.000 V, 60.00 V and 600 V
DC voltage ranges 6.000 V, 60.00 V and 600 V
Resistance range 600.0 Ω to 6.000 MΩ
Continuity threshold Buzzer at 30 Ω or less
Capacitance range 6.000 nF to 600.0 µF
Frequency range with current 6.000 kHz and 10.00 kHz
Frequency range with voltage 6.000 kHz to 100.0 kHz
Frequency accuracy ±1.2% ±3 digits
Maximum conductor capacity 25 mm diameter or 35 × 15 mm

 

Mechanical and General Information
Specification Details
Design Compact, rugged and pocket-sized
Jaw design Elliptical jaw for access around conductors
Maximum jaw capacity 25 mm diameter or 35 × 15 mm
Controls Thumbwheel for single-handed operation
Power supply 2 × 1.5 V AAA alkaline batteries
Carrying method Soft carry case supplied
Warranty 2 years

 

Specification Notes
  • The meter uses True RMS measurement for AC readings.
  • Frequency ranges differ according to whether current or voltage is being measured.
  • Conductor capacity is given as 25 mm diameter or 35 × 15 mm for an elliptical conductor.

What’s Included
  • TL16 lead set
  • 2 × 1.5 V AAA alkaline batteries
  • Soft carry case
  • Instruction manual

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