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1.4 Battery Installation
Refer to section 4.1 (Battery Replacement) for the battery 
installation instructions for the MM68.

2

Specification

MM68

Digital Multimeter

Summary of Contents for MM68

Page 1: ...MM68 MULTIMETER Instruction Manual ...

Page 2: ...ions and for the purposes for which it has been constructed Particular attention should be paid to the Warnings Precautions and Technical Specifications Always check the unit is in good working order before use and that there are no signs of damage to it Do not use if damaged Where applicable other safety measures such as use of protective gloves goggles etc should be employed Please keep these in...

Page 3: ...cription of Terminals 5 3 4 Description of Press Buttons 6 3 5 Description of LCD Symbols 6 3 6 Auto Power Off 6 3 7 Max Min 7 3 8 Relative Function 7 3 9 Backlight 7 3 10 Manual Range Selection 7 3 11 AC DC Voltage Measurement 8 3 12 AC DC Current Measurement 8 3 13 Resistance Measurement 8 3 14 Capacitance Measurement 9 3 15 Frequency Measurement 9 3 16 Duty Cycle Measurement 9 3 17 Continuity T...

Page 4: ...s AC voltage to 750V u DC voltage to 1000V u True rms AC current to 10A u DC current to 10A u Resistance to 220MΩ u Capacitance to 22mF u Frequency to 22MHz u Continuity with audible indication u Diode testing u Duty cycle Further functions are u Max Min indication u Auto power off u Display backlight u Relative function u Auto ranging u Incorrect connection warning 1 3 Accessories included u TL16...

Page 5: ...1 4 Battery Installation Refer to section 4 1 Battery Replacement for the battery installation instructions for the MM68 2 ...

Page 6: ...t connected at the source of the building s low voltage MAINS installation 2 1 Precautions This product has been designed with your safety in mind but please pay attention to the following warnings and cautions before use Warning Before use check the unit for cracks or any other damage Make sure the unit is free from dust grease and moisture Also check any associated leads and accessories for dama...

Page 7: ...nd after using it to determine if a hazardous voltage exists in a circuit to be tested Warning When using test leads always keep your fingers behind the finger guard on the test lead probe Warning Measuring a voltage that exceeds the specified limits of the unit may damage the unit and expose the operator to a shock hazard Always check the unit s specified limits before use Caution Avoid severe me...

Page 8: ...ltage and the voltage magnitude is unknown set the range to 1000V then if required select autoranging for a satisfactory reading If a test lead is connected to the wrong input socket when a voltage range is selected then a warning buzzer will sound If the multimeter displays OL or OL then the measurement limits of the range have been exceeded 3 2 Low Battery Indication If the symbol is displayed t...

Page 9: ...3 5 Description of LCD Symbols APO Auto power off is active RANGE Manual ranging is selected Diode testing function is selected Continuity function is selected Relative function is selected MAX Maximum indication is selected MIN Minimum indication is selected mV V A nF Unit of measurement being displayed μF mF Ω kΩ MΩ Hz kHz Indicates battery is low DC Indicates DC measurement AC Indicates AC meas...

Page 10: ...o remove an offset residual value from a measurement To select the relative function press the button to store the offset residual value This will now be removed from all consequent readings while the relative function is selected Press the button again to exit the relative function 3 9 Backlight Press the button to turn on off the backlight The backlight will automatically turn off after approx 4...

Page 11: ...d to the COM terminal and the red test lead to the μA mA or 10A terminal depending on the magnitude of current to be measured Set the rotary switch to either the AC or DC ranges as required Taking all necessary safety precautions connect the test leads in series with the circuit being measured and read the measured current from the display 3 13 Resistance Measurement Connect the black test lead to...

Page 12: ... the measured capacitance from the display 3 15 Frequency Measurement Connect the black test lead to the COM terminal and the red test lead to the HzVΩ terminal Set the rotary switch to Hz and if required press the Hz button to select the frequency function If required manually set the range Taking all necessary safety precautions connect the test leads to the circuit being measured and read the m...

Page 13: ... the resistance is 30Ω 3 18 Diode Testing If the diode to be tested is in circuit be sure the circuit power is switched off Connect the black test lead to the COM terminal and the red test lead to the HzVΩ terminal Set the rotary switch to Taking all necessary safety precautions connect the test leads to the diode being tested If the diode is good a forward bias will give a display reading of arou...

Page 14: ...r disconnect the multimeter from any external circuits or components and remove the test leads before proceeding Replace only with the fuse specified Replace the fuses by removing the three screws securing the rear casing and lift off the rear casing Replace F1 only with the original type 0 5A 500V fast acting ceramic fuse and replace F2 only with the original type 10A 500V fast acting ceramic fus...

Page 15: ...or detergents which can be conductive 4 6 Repair Service There are no user serviceable parts in this unit other than those that may be described in section 3 Return to Martindale Electric if faulty Our service department will quote promptly to repair any fault that occurs outside the guarantee period Before the unit is returned please ensure that you have checked the unit batteries fuses poor conn...

Page 16: ...of Martindale Martindale s warranty obligation is limited at Martindale s option to refund of the purchase price free of charge repair or replacement of a defective product which is returned to Martindale within the warranty period This warranty is the buyer s sole and exclusive remedy and is in lieu of all other warranties expressed or implied including but not limited to any implied warranty of ...

Page 17: ...ision maker of competent jurisdiction such holding will not affect the validity or enforceability of any other provision or other part of that provision Nothing in this statement reduces your statutory rights ...

Page 18: ...oad protection 1000V DC or 750 AC rms TRUE RMS AC VOLTS Ranges 220mV 2 2V 22V 220V 750V Resolution 0 01mV 0 0001V 0 001V 0 01V 0 1V Accuracy 220mV range 50 Hz to 500 Hz 1 2 of rdg 10 dgts 2 2V to 220V ranges 50 Hz to 500 Hz 1 2 of rdg 10 dgts 500 Hz to 2 kHz 2 0 of rdg 20 dgts 750V range 50 Hz to 500 Hz 2 0 of rdg 20 dgts AC coupled true rms specified from 5 to 100 of range Crest factor 3 Input im...

Page 19: ...220mA 10A Resolution 0 01μA 0 1μA 0 001mA 0 01mA 0 001 A Accuracy 220μA to 220mA 50 Hz to 1 kHz 1 5 of rdg 5 dgts 10A range 50 Hz to 1 kHz 2 5 of rdg 5 dgts Current on 10 A range applied for 60 seconds max followed by a 10 minute cooling period AC coupled true rms specified from 5 to 100 of range Crest factor 3 Input protection 0 5A 500V fast blow ceramic fuse 10A 500V fast blow ceramic fuse RESIS...

Page 20: ...rdg 20 dgts Overload protection 500 V DC or AC rms FREQUENCY Ranges 22Hz 220Hz 22kHz 220kHz 2 2MHz 22MHz Resolution 0 01Hz 0 1Hz 0 001kHz 0 01kHz 0 0001MHz 0 001MHz Accuracy 0 1 of rdg 3 dgts Input sensitivity 2Hz 2 2MHz 2 5Vrms 2 2MHz 22MHz 2 5Vrms and 5Vrms Minimum input 22Hz range 2Hz 220Hz range 20Hz Minimum pulse width 25ns Duty cycle limits 30 and 70 Overload protection 500VDC or AC rms DUTY...

Page 21: ...22000 Analog bargraph 22 segments with measurement 20 times per second Polarity Automatic positive implied negative polarity indication Overrange OL or OL is displayed Zero Automatic Low battery indication symbol is displayed when the battery voltage drops below the operating level Measurement rate 3 times per second nominal Auto power off After approx 30 minutes Operating environment 0 C to 50 C ...

Page 22: ...ncludes TL16 test leads 1 x spare fuse 9V battery installed and instructions SAFETY Conforms to BS EN 61010 1 CAT III 600 V CAT II 1000V Class II Double Insulation Pollution Degree 2 for indoor use TL16 test leads conform to BS EN 61010 031 CAT III 1000V CAT IV 600V 10A EMC Conforms to BS EN 61326 ...

Page 23: ...USER NOTES ...

Page 24: ...s Accessories l Phase Rotation Testers l Proving Units l Socket Testers l Thermometers Probes l Test Leads l Voltage Indicators l Specialist Metrohm Testers 4 5kV l Specialist Drummond Testers Check out what else you can get from Martindale Martindale Electric Company Limited Metrohm House Imperial Park Imperial Way Watford WD24 4PP UK Tel 44 0 1923 441717 Fax 44 0 1923 446900 E mail sales martind...

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