Tenma 72-3530 - Measuring AC;DC Voltage; AC;DC Voltage Measurement Details; Voltage Measurement Caution

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communication on/off, “bEEp” (key beep) for buzzer switch on/off, “ALO” (ALO
time) for automatic light off, “APO” (APO time) for automatic power supply off,
“DEL” (format MEM) for memory formatting.
• Short press the arrow button to select an item and short press HOLD to exit the
setting menu.
• You can alter the parameters of the setting items through the RANGE or MAX MIN
buttons.
• If the parameter displayed on the auxiliary display is “YES”, the operation of
memory formatting will be executed by short pressing SELECT and all of the data
saved will be cleared.
SELECT/V.F.C - button of selection/measurement on voltage or current to
frequency conversion
• Press SELECT to choose the function.
• Press and hold V.F.C for two seconds in AC voltage mode and the LCD will display
“V.F.C”.
• It will be allowed to enter the mode of V.F.C measurement on voltage to frequency
conversion.
• Press and hold the button again and it will exit the mode of V.F.C measurement.
• In mV gear, press and hold SELECT to enter or exit the function of temperature
measurement.
• In µA gear, press and hold SELECT to enter or exit % (4-20mA).
MEASURING
• Before measuring, check the built-in battery.
• If the low battery symbol is showing on the LCD, then change the battery
immediately or charge before use.
• Watch out for the ! symbol beside the probe socket, which warns you of not
exceeding the indicated gure for voltage or current under test.
MEASURING AC/DC VOLTAGE
• The AC measuring displayed value is the true virtual value. During in-circuit
measurement, press the Hz/% button to select the mode of Measurement on
Frequency/Duty Ratio for the auxiliary display.
• In the DC voltage function gear, press SELECT to choose the mode of AC and DC
measurement.
• Press the Hz/% button and the auxiliary display will show AC/DC/Hz values in
order and the AC and DC value will be on the main display.
Caution
• If the input impedance of the instrument, which is about 10MΩ, is higher than the
load, it will cause an error in measurements of high-impedance circuits.
• Mostly, if a circuit is lower than 10k, errors can be ignored (0.1% or lower).
• Do not input voltage higher than 1,000Vrms. It is possible to measure higher
voltage, but it is very likely to damage the instrument.
• It’s recommended to test a known voltage before use in order to conrm that the
product is functioning correctly.