FUNCTION : MEASURING RANGE
VOLTAGE DC : 10V / 50V / 250V / 500V
VOLTAGE AC : 50V / 250V / 500V
CURRENT DC : 25m / 250mA
RESISTANCE : Rx10 / Rx1KΩ
BATTERY TESTER : 1.5V / 9V
dB : 4 to 56dB
FUSE : 0.5A / 250V 5 x 20mm FAST ACTING
BATTERY : 1 x 1.5V (AAA)

MODEL: EM-666
PACKING DIMENSION: L16cm x W3cm x H21.5cm
WEIGHT: 0.25KG

MEASURING DC VOLTAGE 
1. Set the range switch to the desired V ⎓ range position. If the magnitude of the voltage to be measured is not known beforehand, set the highest range first and then work down range by range if necessary.
2. Connect the red test leads to the positive side of the circuit to be measured and the black test lead to the negative side of the circuit.
3. Use the chart below as a guide to reading DC voltage measurement:

MEASURING DC CURRENT
1. Set the range switch to desired mA ⎓ range position. If the magnitude of the current to be measured is not known beforehand, select the highest range first and then work down range by range if necessary.
2. Turn off power to the circuit which you will measure. Discharge all capacitors.
3. Break the circuit path to be measured, connect the red test lead to more positive side of the break and the black test lead to the more negative side of the break.
4. Turn on power to the circuit.
5. Use the chart below as a guide to reading DC current measurements:

Measuring AC VOLTAGE
1. Set the range switch to desired V ~ range position. If the magnitude of the voltage to be measured is not known beforehand, select the highest range first and work down range by range if necessary.
2. Connect the test leads across the circuit to be tested.
3. Use the chart below as a guide to reading AC voltage measurements:

MEASURING RESISTANCE
1. Set the range switch to desired Ω range position.
2. Short the test leads and turn the “0Ω ADJ” knob until the pointer is in the zero position of the top scale (the “OHMS” scale).
Note: If it is impossible to set the pointer to the zero position, the battery is low and should be replaced.
3. Make sure that the load to be tested is without power.
4. Connect the test leads to the load.
5. Read the top scale, multiply the reading you get on the scale by the factor (1k or 10) marked on the selected range to get the final measurement result.

DECIBEL MEASUREMENT
Decibel is measured in the same way as AC voltage measurement reading the “dB” scale (the fifth scale) instead.
For measurements in the ACV 50V range, the dB scale is read directly. If the reading is higher than +36dB, use the 250V, 500V range, and add a fixed sum of dB to respective reading as follows:
For ACV 250V range, add 14dB to the reading.
For ACV 500V range, add 20dB to the reading.
Note:
When measuring a signal which contains a direct current, a 0.1μF block capacitor with the voltage endurance of more than 500V should be connected in series.

BATTERY TEST
1. Set the range switch to the desired BAT. range (9V or 1.5V).
2. Connect the red test lead to the positive terminal of the battery to be tested and the black test lead to the negative terminal of the battery.
“GOOD” area of the “BATT.” scale indicates that the battery is good.
“BAD” area indicates that the battery is low.
“?” area indicates that the battery’s condition is marginal.

BATTERY AND FUSE REPLACEMENT
If the pointer cannot be set to the zero position of the top scale with the “0Ω ADJ.” knob while the range switch is in a Ω range position and the test leads are being shorted, the battery is low and should replaced immediately.
If the meter doesn’t work, you should replace the fuse.
To replace battery or fuse, remove the screws on the back cover, remove the back cover, replace the battery or fuse according to the specified rating. Reinstall the back cover and the screws.
Fuse: 500Ma / 250V, Fast action, Ø5x20mm
Battery: 1.5V, AAA or equivalent, one piece