Digital Multimeter HDM3055 Series Manual

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Frequency and Period

This section describes how to configure frequency and period measurements from the front panel.

Step 1: Configure the test leads as shown.

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Step 2: Press on the front panel to open a menu that specifies

whether the DMM will beep to indicate a successful diode test.

Diode measurements behave as follows:

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Diode

This section describes how to configure diode tests from the front panel. The range and resolution

are fixed; the range is 10 VDC (with a 1 mA current source output).

Step 1: Configure the test leads as shown.

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Continuity measurements behave as follows:

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Step 2: Press [Cont] on the front panel to open a menu where you can enable or disable the beeper

for all functions that use the beeper (limits, probe hold, diode, continuity, and errors).

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Continuity

This section describes how to configure continuity tests from the front panel.

Step 1: Configure the test leads as shown.

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Step 4: Press Range to select a range for the measurement. You can also use the [+], [-], and

[Range] keys on the front panel to select the range. (Auto (autorange) automatically selects the

range for the measurement based on the input. Autoranging is convenient, but it results in slower

measurements than using a manual range. Autoranging goes down a range at less than 10% of

range and up a range at greater than 120% of range. For capacitance measurements only, when

autorange is off, the instrument does not report an overload for readings greater than 120% of range.

Overload only occurs when the algorithm times out because the applied capacitance is too large for

the algorithm to measure. If you apply a DC voltage or a short to the input terminals in capacitance

measurement mode, the instrument reports an overload.

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Step 2: Press

on the front panel.

Step 3: To null–out the test lead capacitance:

l Disconnect the + and - test leads probe end from the test circuit, and leave open.

l Press Null. The DMM will now subtract this null value from capacitance measurements.

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Capacitance

This section describes how to configure capacitance measurements from the front panel.

Step 1: Configure the test leads as shown.

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Step 5: Use the Units softkey to display temperature in degrees Celsius, degrees Fahrenheit, or Kelvin.

Thermistor Requirements

The DMM converts the measured thermistor resistance to temperature using the Steinhart-Hart thermistor equation:

1?T = A + B (Ln(R)) + C (Ln(R))3

A, B, and C are constants provided by the thermistor manufacturer and derived from three

temperature test points.

R = Thermistor resistance in Ω.

T = Temperature in degrees K.

Important: Use only a 5 k? 44007-type thermistor. This type thermistor has constants of A = 1.285e-3, B = 2.362e-4,

C = 9.285e-8. Using an incorrect type of thermistor can result in errors greater than 20 °C for a temperature being

measured of 100 °C.