45

Users Manual

Measuring Voltage, Resistance, or Frequency

To measure voltage, resistance, or frequency, press the desired function button and connect the test leads as shown in Figure 2-5. The meter will select the appropriate range in the autorange mode, and an annunciator on the display will indicate measurement units.

Note

After measuring high voltage to 1000 V dc, errors may occur when making measurements with 1 to 10 µV resolution. Allow up to two minutes prior to making low-level measurements.

Measuring Current

To measure current, insert the test leads in the 100 mA input terminal for currents up to 100 mA or in the 10 A input terminal for higher current. Press Cor Dand connect the test leads as shown in Figure 2-6 and described in the following procedure:

1.Turn off power in the circuit to be measured.

2.Break the circuit (on the ground side to minimize the common mode voltage), and place the meter in series at that point. (To measure current without breaking the circuit, use a current clamp.)

3.Turn on power to the circuit, and read the display. The meter will select the appropriate range automatically, and an annunciator on the display will indicate the units of the measurement value shown.

4.Turn off power to the circuit and disconnect the meter from the tested circuit.

Note

After measuring high current using the 10 A input, thermal voltages are generated that may create errors when making low-level (high sensitivity) dc measurements of volts, current, or ohms. To make the most accurate measurements, allow up to ten minutes for the thermals to settle out.

Diode/Continuity Testing

Diode and continuity tests are performed by a diode test function with a continuity beeper that can be turned on and off.

The continuity test determines whether a circuit is intact (i.e., has a resistance less than about 30 ). The meter detects continuity for intervals as brief as 50 µs. The continuity test function cannot be selected for the secondary display.

To perform a continuity test, press G, and connect the test leads as shown in Figure 2-7. The beeper emits a single beep when the input drops below +0.8 V (approximately 1 k), and emits a continuous tone when the input goes below +25 mV (approximately 30 ).

The diode test measures the forward voltage of a semiconductor junction (or junctions) at approximately 0.7 mA. Readings are displayed in the 3 V range at the medium and fast measurement rates. "OL" is displayed for voltages above +2.5 V. If the diode test is performed at the slow reading rate, readings are displayed in millivolts on the 1000 mV (1 V) range.

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Fluke 45 user manual Measuring Voltage, Resistance, or Frequency, Measuring Current, Diode/Continuity Testing

45 specifications

The Fluke 45 is a versatile and high-precision Digital Multimeter that is designed for a wide range of applications in electrical testing, troubleshooting, and maintenance. Known for its reliability and advanced features, the Fluke 45 is an essential tool for engineers, technicians, and professionals who require accurate measurement capabilities.

One of the standout features of the Fluke 45 is its ability to measure both AC and DC voltage and current. With a maximum input voltage of 1000 volts and current ranges up to 10 amps, users can conduct a variety of electrical tests with confidence. The device is equipped with an intuitive dual display, allowing for simultaneous viewing of multiple measurements. This feature enhances usability during complex diagnostics.

The Fluke 45 also boasts an impressive resolution of 0.1 mV and a basic accuracy of 0.25%, which translates to highly reliable readings. The auto-ranging capability simplifies the measurement process, automatically selecting the appropriate range based on the input signal, thus saving time and reducing user error.

In addition to voltage and current measurements, the Fluke 45 features resistance measurement capabilities, with a range of up to 40 MΩ. This makes it an effective tool for testing circuits, identifying faults, and ensuring the integrity of electrical systems. The continuity test function, complete with a built-in beeper, assists in quickly diagnosing wiring issues.

Another remarkable characteristic of the Fluke 45 is its frequency measurement capabilities, which can measure frequencies up to 1 MHz. This is particularly useful in applications involving signal analysis and troubleshooting oscillators.

Moreover, the Fluke 45 is designed with user convenience in mind. It is lightweight and portable, making it easy to carry around, whether on a job site or in a workshop. The rugged construction, reinforced with high-quality materials, ensures it can withstand harsh conditions often encountered in the field.

To enhance functionality, the Fluke 45 features a data hold function that freezes the displayed measurement for easier reporting. Additionally, it can store data for later retrieval, making it convenient for users who need to compile test results over time.

In summary, the Fluke 45 Digital Multimeter is an advanced instrument that combines precision, versatility, and user-friendly design. Its wide measurement capabilities, high accuracy, and durable build make it an invaluable tool for professionals in diverse electrical and electronic applications. Whether for routine maintenance or complex troubleshooting, the Fluke 45 stands out as a reliable partner in achieving accurate and efficient results.