Martindale CM57 AC TRMS Clamp Multimeter

The CM57 from Martindale is a TRMS 600V AC Clamp Meter. Boasting a good range of basic features coupled with the great low price, this clamp is ideal for commercial and industrial applications.

Next Day Delivery (subject to availability)

including VAT @ 20%
Regular Price:
  • Tests up to 600A
  • Current AC
  • TRMS
  • Data Hold
  • Resistance Measurement
  • Continuity Measurement
  • Voltage AC/DC
  • 25mm Jaw Size
  • FreeDelivery
  • 30DayMoneyBack
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Martindale CM57 AC TRMS Clamp Meter

The CM57 is a new pocket sized high performance AC Clamp meter measuring AC current, AC/DC voltage, resistance with continuity test plus capacitance, frequency and diode test. The compact rugged design enables accurate and reliable current measurement down to 10mA resolution without the need to break into the circuit.

True RMS measurement ensures reliable readings with distorted waveforms often caused by modern lighting and power supplies.

Features include a thumbwheel for single handed operation, auto ranging for ease of use, auto power off and low battery indicator plus a high contrast backlit display with hold function useful for working in low light and hard to reach areas. The Smart function automatically detects and switches between resistance and capacitance measurements.

The CM57 has a CATIII 600V safety rating and includes a non-contact voltage sensor built into the jaw for detecting the presence of AC voltages.


The CM57 TRMS Clamp Meter Comes Supplied With:

  • Martindale TL16 Test Leads
  • Soft Carry Case
  • Alkaline Batteries
  • All Martindale clamp meters come with a 2 year warranty.


Key Features:

  • TRMS Meter
  • Voltage, Resistance, Continuity, Capacitance, Frequency and Diode tests
  • Single Handed Operation
  • Auto ranging
  • Auto switching between resistance and capacitance measurements
  • CAt III 600 Rated
  • Built-in non contact voltage sensor


Martindale CM57 TRMS AC Clamp Meter
 DC Voltage
Range  Resolution Input Impedance   Accuracy     
 6V 0.001V    10M    1.0% + 3 
 60V  0.01V
 600V  0.1V
 Overload protection: 660V DC or AC rms
 AC Voltage
 Range  Resolution  Input Impedance  Accuracy
(50 to 400Hz) 
 6V  0.001V    10  
 60V  0.01V 1.2% + 5 
 600V  0.1V  
 Range Resolution  Sensitivity  Accuracy 
  AC Current  6Khz 0.001Khz   3A    0.2% + 2  
 10Khz 0.01Khz   5A
  AC Voltage   6Khz 0.001Khz    5V rms 
60Khz  0.01Khz 
 100Khz  0.1Khz
 Range  Resolution  Max. Test Voltage  Accuracy        
 6nF 0.001nF     -1.5V DC     3.0% + 30
 60nF  0.01nF    3.0% + 10  
 600nF  0.1nF
 6µF  0.001µF
 60µF  0.01µF
 600µF  0.1µF
 Minimum Capacitance Measurement 0.3nF
 Overload Protection 450V DC or AC ms
 Non-contact Voltage Indicator range 90V to 600V (50-60Hz)
 AC Current
Range   Resolution  Accuracy    
 (50-60Hz) (60-400Hz)   
 60A 0.01A    1.9% + 5   3.0% + 5  
600A  0.1A   
Range  Resolution  Sensitivity  Accuracy   
600   0.1   1.5V DC         1.2% + 3  
 6K  0.001K  
60K  0.01K   
600K   0.1K  
6M  0.001M   
 Open Circuit Voltage   Audible Indication  
-1.5V DC   30  
Overload protection 450V DC or AC rms

Standard Delivery 3-5 Day Delivery – UK
£2.95 for all all orders under £40.00 (exld vat). Sent by Royal Mail Tracked, delivered/posted within 3-5 working days from the date of your order, subject to availability.

Standard Free Delivery 3-5 Day Delivery – UK Mainland only - Zone A & B
Included in the price for all orders over £40.00 (exld vat). Sent using FedEx, delivered within 3-5 working days from the date of your order, subject to availability.

Express DPD Delivery 1-2 Day Delivery – UK Mainland only - Zone A & B
£4.50 select at the checkout. Sent using DPD on their Award Winning “Predict” Service with these great key benefits:

  • You are given a one hour delivery window. (no more waiting in all day for your parcel)
  • You are notified by text or e-mail on your parcels progress.
  • Change of plan? You can easily use the text or e-mail to rearrange your delivery.
  • Notifications on your parcel up to 15 minutes before delivery.

Orders must be placed before 3pm for next day delivery and a mobile number supplied, subject to availability.

Next Day Delivery – UK Mainland only - Zone A & B
£8.00 select at the checkout. Sent using FedEx, orders must be placed before 3pm for next day delivery, subject to availability.

Saturday Pre 12am - UK Mainland only - Zone A & B
£15.00 select at the checkout. Sent using FedEx, orders must be placed before 3pm for Saturday delivery.

Delivery Surcharges
Because of the high cost of carriage we need to apply a surcharge on all deliveries made in the following regions: 

  • Scotland, Isle of Wight & Isles of Scilly - £6.00  
  • Scottish Highlands and Northern Ireland - £12.00  Zone C
  • Scottish Islands, Isle of Man and Channel Islands - £14.00  Zone D
  • Southern Island - £15.00  Zone E


 International delivery

International delivery charges are automatically added to your order at the checkout; you can also use the guide below for a guide on prices. For any questions regarding international deliveries please contact us at

 Zone 1:

  • France, Germany, Belgium, Netherlands, Luxembourg. £20.00 per parcel

Zone 2:

  • Austria, Denmark. £22.00 per parcel
  • Liechtenstein, Switzerland £47.00 per parcel (added cost for custom clearance surcharge)

Zone 3:

  • Czech Republic, Italy, Slovakia, Spain. £28.00 per parcel

Zone 4:

  • Estonia, Finland, Hungary, Poland, Portugal, Slovenia, Sweden. £50.00 per parcel

Zone 5:

  • Bulgaria, Croatia, Greece (incl islands) Latvia, Lithuania, Romania. £60.00 per parcel

Bosnia-Herzegovina, Iceland, Norway, Serbia. £85.00 per (added cost for custom clearance surcharge)

If no shipping option is available to your selected country.  Please call us on +44 (0) 1603 406 148 to purchase your items.