Applications 4

How the Meter Makes Dual Display Measurements

level, range type (autorange or manual range), the measurement rate (slow, medium, or fast), and whether measurement types are mixed or not. (Measurements are either ac-type [ac volts or amps] or dc-type [all others]).

Typical response times for a single measurement are shown in Table 4-2. For a single measurement, results are displayed as soon as the correct range is found. However, additional time needs to be allowed for the measurement to be fully settled in order for the displayed result to meet the meter’s accuracy specifications. This "settling delay" varies, depending on the differences between the primary and secondary displays.

The settling delay is longer when ac- and dc-type measurements are mixed. Examples of mixed ac and dc measurements are volts dc and amps ac, and volts ac and amps dc. Settling times are listed in Table 4-3.

How the Meter Makes Dual Display Measurements

When the meter is in the dual display mode (i.e., both the primary and secondary displays are on), the meter takes measurements and updates the displays in one of two ways: (1) it takes a single measurement and updates both displays using that measurement; or (2) it updates each display using a separate measurement.

Note

When measuring AC + DC, (or any dual display combination of AC and DC) in the fast reading rate, the Fluke 45 may show significant reading errors. This results from a lack of filtering on the DC portion of the measurement for the fast reading rate. To avoid this problem, use only the "slow" and "medium" reading rates for AC + DC or AC and DC combinations.

Updating the Primary and Secondary Displays with a Single Measurement

The meter takes a measurement and updates both displays using that measurement only when the meter is in the autorange mode, and the measurement function and range are the same for both the primary and secondary displays.

This will happen, for instance, if dB (which always causes the voltage measurement in the primary display to autorange) or HOLD (with autoranging on) is applied to a measurement function on the primary display and the same function is selected for the secondary display.

If for example, the dB value of an ac voltage measurement were shown in the primary display and the ac voltage itself were shown in the secondary display, the meter would take a single measurement and update both displays with it.

Updating the Primary and Secondary Displays with Separate Measurements

If the measurement function, range, and ranging mode in the primary display are not identical to those in the secondary display, the meter updates each display using a separate measurement.

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Fluke 45 user manual How the Meter Makes Dual Display Measurements
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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.
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