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Crucial safety advice for avoiding false readings and potential injury.
Explanation of common symbols used for safe operation.
Critical safety warning against using Touch Hold for dead circuit verification.
Stray voltages can affect readings in Touch Hold mode.
Essential safety warning for current measurements and fuse protection.
Safety warning on test leads, case closure, and fuse usage.
Cautionary note on handling components and avoiding static damage.
Important note on safety precautions before opening the meter case.
Crucial safety advice for avoiding false readings and potential injury.
Explanation of common symbols used for safe operation.
Critical safety warning against using Touch Hold for dead circuit verification.
Stray voltages can affect readings in Touch Hold mode.
Essential safety warning for current measurements and fuse protection.
Safety warning on test leads, case closure, and fuse usage.
Cautionary note on handling components and avoiding static damage.
Important note on safety precautions before opening the meter case.
The Fluke 70/73 Series III Multimeter is a versatile instrument designed for electrical measurements, offering a range of functions for both professional and hobbyist use.
The multimeter is capable of measuring various electrical parameters, including AC and DC voltage, resistance, and current (for the 73 model). It also features a diode test and continuity test function.
For voltage measurements, the device can handle both AC and DC voltages, with specific ranges for millivolts DC. This allows for precise readings in different circuit conditions. Resistance measurements are performed by turning off power to the circuit and discharging all capacitors, ensuring accurate readings by eliminating external voltage interference.
The diode test function allows users to check the forward and reverse bias of diodes. A good diode in forward bias will show a specific reading and emit a single beep, while in reverse bias, it will display "OL" (Overload). Bad diodes will show "OL" in forward bias or "000" if shorted. The continuity test function quickly identifies continuous circuits (resistance less than 210 Ω) by emitting a continuous beep. If the meter is in Automatic Touch Hold® mode, it will beep twice.
Current measurements (available on the 73 model) can be performed for both AC and DC current. Users must ensure the open circuit voltage is below the meter's rated voltage to prevent injury and use the 10 A jack for currents up to 300 mA to avoid blowing the input fuse. The process involves turning off circuit power, breaking the circuit, placing the meter in series, and then turning power back on.
The multimeter incorporates several features to enhance usability and safety.
Safety Information: Before any use, it is crucial to review the safety information. This includes checking the meter and test leads for damage, ensuring correct positioning of test leads and the rotary switch, and never measuring resistance in a powered circuit. Users are warned against touching probes to a voltage source when leads are in the 10 A or 300 mA input jacks and against using the meter on circuits exceeding 4800 volt-amps. It is also important not to apply more than the rated voltage between any input jack and earth ground. Caution is advised when working with voltages above 60 V dc or 30 V ac rms due to shock hazards, and users should always keep fingers behind the finger guards on the test probes. A warning indicates that the battery should be replaced as soon as the battery indicator appears to avoid false readings and potential electric shock or injury.
Input Jacks: The meter has dedicated input jacks for Amps (10A and 300mA FUSED), Volts, Ohms, Diode Test, and a Common Terminal. These are clearly labeled to guide correct lead placement.
Pushbutton: A versatile pushbutton allows users to select a fixed range or activate the Automatic Touch Hold® mode.
Autorange and Manual Range: The meter defaults to autorange when powered on, simplifying initial setup. For specific measurement needs, manual ranging is available for V ac, V dc, ohms, A ac, and A dc. To return to autorange, the pushbutton can be pressed for 1 second or the rotary switch can be turned.
Automatic Touch Hold® Mode: This mode automatically captures and displays stable readings. It can be activated by pressing the pushbutton for 2 seconds while turning the meter on. When a new input is captured, the meter beeps, and the new reading is displayed. To manually force a new measurement, the pushbutton can be pressed. It is important to note that stray voltages can produce new readings. To exit this mode, the meter must be turned off. A critical warning states that this mode should not be used to determine if a high-voltage circuit is dead, as it may not capture unstable or noisy readings, potentially leading to electric shock.
Bar Graph: The integrated bar graph visually represents readings relative to the full-scale value of the displayed measurement range and indicates polarity, providing a quick analog representation of the measurement.
Standby: To conserve battery life, if the meter is inactive for an hour (or 20 minutes in diode test mode), the screen will go blank and display selected bar graph segments. Operation can be resumed by turning the rotary switch or pressing the pushbutton.
Holster: The multimeter comes with a snap-on holster that absorbs shocks and protects the device. It also includes a Flex-Stand™ for convenient positioning. To protect the meter's front, it should be placed face down in the holster.
Proper maintenance ensures the longevity and safe operation of the multimeter.
Cleaning: The meter should be cleaned with a damp cloth and mild detergent. Abrasives or solvents should not be used, as they can damage the device.
Battery and Fuse Replacement: A warning emphasizes the importance of removing test leads and turning the rotary switch to OFF before opening the case to avoid electric shock. To prevent fire and possible arc-flash, only fuses with the specified ratings (found on the back of the meter) should be used. When replacing the battery, users are cautioned to lift the end of the battery as shown to avoid damaging meter components. To prevent contamination or static damage, the circuit board should not be touched without proper static protection. The manual provides a diagram for internal fuse testing and replacement, indicating the location of fuses F1 and F2.
General| Model | Fluke III Series |
|---|---|
| Category | Multimeter |
| Display | LCD |
| Diode Test | Yes |
| DC Voltage Range | 0.1 mV to 1000 V |
| AC Voltage Range | 0.1 mV to 750 V |
| Continuity | Yes |
| Digits | 3.5 |
