Monarch 120 , 4.0 Control Functions:

MODEL 120 TRUE RMS MULTIMETER

Manual range indication Maximum indication

Relative indication Revolutions per minute

Auto range indication Minimum indication

Data hold indication Peak max/min indication

Low battery indication Diode indication

RS-232 indication Continuity with beeper

AC source Temperature indication

DC source Capacitance indication

Negative polarity indication Voltage/current indication

Auto power off indication Frequency indication

Digital value indication Resistance indication

Analog bar indication

4.0 Control Functions:

4.1 Func tion Selector Rotary Switch

The rotary switch turns power on to the instrument and selects the function to be

measured. The primary functions available are printed in red and white on the instrument

scale. Alternate functions, accessed in conjunction with the blue Second Function

Button, are printed in blue.

4.2 Range Button

The instrument powers on in the Auto Range mode, as indicated by the

‘AUTO’

indicator

in the display. To select a Manual Range, press the

RANGE

button which will lock the

meter in its’ present range and bring on the

MANU’

indicator in the display. Each

subsequent press of the

RANGE

button circulates the instrument to the next higher range

or wraps from the highest back to the lowest range. To exit the Manual Range mode and

return to Auto Range, press and hold the

RANGE

button for one second.

4.3 MAX/MIN Button

The Maximum and Minimum values are the highest and lowest values displayed during

the time the instrument is in the MAX/MIN mode. To display Maximum and Minimum

values, first ensure the value will not exceed the measurement range selected. Press the

MAX/MIN

button once to display the Maximum value, as indicated by the ‘

MAX’

indicator in

the display. Press it again to display the ‘

MIN’

value and indicator. Press it once more to

display the current value. In this selection, the

‘MAX/MIN’

indicator will flash. To exit the

MAX/MIN mode, press and hold the

MAX/MIN

button for one second.

4.4 Data Hold Function

To hold the current measured value, press the

HOLD

button. Press the

HOLD

button again

to release the held data and return to continuous reading.

4.5 Peak Hol d Function

This instrument is equipped with a 1ms Peak capture capability in the ACA, ACV, DCA

and DCV ranges. The Peak values are the highest and lowest transient values captured

by the instrument, regardless of whether or not they might be displayed in the normal

measuring mode. To display Peak values, first ensure the value will not exceed the

measurement range selected. The instrument must then conduct an internal self-

calibration, which calculates and stores the offset voltage in preparation for capturing a

high speed Peak value.

To invoke the calibration operation, press and hold the

PEAK

button for approximately 2

seconds until

‘CAL’

appears in the display. The instrument is now calibrated to properly

capture Peak values.

Press the

PEAK

button again to display the Maximum Peak, as indicated by the ‘P

MAX’

indicator in the display. Press it once more to display the ‘P

MIN’

value and indicator.

Press and hold the

PEAK

button for 2 seconds to exit the Peak mode.

Note: The instrument must be calibrated in accordance with the above procedure

whenever the function range is changed.

MODEL 120 TRUE RMS MULTIMETER

5.4 Resistance Measurements

WARNING

Before making any in-circuit measurements, remove power from the circuit

being tested and discharge all capacitors in the circuit.

1. Connect the red test lead to the

‘

’

jack and the black test

lead to the

‘COM’

jack.

2. Set the Function Selector switch to the

:

function.

3. Ensure there is no power applied to the circuit, and then

connect the test leads in parallel with the circuit being

tested and read the measured resistance on the instrument

display.

5.5 Continuity Measurements

WARNING

Before making any in-circuit measurements, remove power from the circuit being tested and discharge all

capacitors in the circuit.

1. Connect the red test lead to the

‘

’

jack and the black test lead to the

‘COM’

jack.

2. Set the Function Selector switch to the

:

function.

3. Press the blue Second Function button once to select the function.

4. Ensure there is no power applied to the circuit, and then connect the test leads in

parallel with the circuit being tested.

5. When the impedance between the test leads is less than 40:a continuous beeper

will activate.

Open Circuit Short Circuit

5.6 Diode Tests

WARNING

Before making any in-circuit measurements, remove power from the circuit

being tested and discharge all capacitors in the circuit.

1. Connect the red test lead to the ‘ ’ jack and the black

test lead to the ‘

COM

’ jack.

2. Set the Function Selector switch to the

ҏҏҏҏҏfunction.

3. Press the blue Second Function button twice to select the

function.

4. Ensure there is no power applied to the circuit, and then

connect the red test lead to the anode side and the black

test lead to the cathode side of the diode being tested.

5. Read the Forward Voltage (V

) on the instrument display.

Note: If the polarity of the test leads is reversed, the display will read ‘OL’. This can be

used to determine the anode and cathode terminals of a diode.