ANALOG MULTIMETER
CP7849
OPERATING INSTRUCTIONS
Instrucciones en
Español e Inglés
GENERAL DESCRIPTION
The CP7849 Analog Multimeter is a rugged, accurate, easy-to-operate,
compact instrument. The stable linear meter movement allows it to make
accurate measurements of AC and DC voltages, DC currents in the
milliamp range, resistance, and decibels. The multimeter uses the most
modern components and circuit techniques designed in a high-impact
case. If the tester is kept clean and is not subjected to extreme shock or
continuous vibration, it will provide many years of trouble-free service.
SPECIFICATIONS
ELECTRICAL
Range: 19 measuring ranges
DC voltage: 0-2.5-10-50-250-500 volts
AC voltage: 0-10-50-500 volts
DC current: 0-0.5-10-250 mA
Resistance: RX10 Ohm, RX1kOhm
Decibel: -10 dB to 56 dB at AC volt ranges
Accuracies: DC V/mA, AC V, Resistance 5% of Full Scale
BAT test: 1.5V and 9V batteries 10% of Full Scale
MULTIMETER BASIC FUNCTIONS
1. Protective boot
2. Meter
3. OHMS: This function is used for measuring the resistance of a com-
ponent.
4. Zero Adjuster: A thumbwheel adjustment located on the left side of
the multimeter. The zero adjuster is used to zero the meter pointer
when making resistance measurements.
5. AC VOLTS: This function is used for measuring AC (Alternating Current) voltages.
6. BAT: This function is used for testing 1.5V and 9V batteries under
load.
7. Protective Caps: Keep the caps on when the multimeter is not in
use.
8. Test leads
9. OFF: When the multimeter is not in use, keep the function range
switch in the OFF position.
10.
DC VOLTS: This function is used to measure DC (Direct Current)
voltages.
0002-000-2485
11.
Function range switch: A 16 position switch located at the center of
the meter. This switch is used to select the function and range to be
measured.
12.
DC milliamps: This function is used for measuring the DC Current
(Direct Current).
13.
Mechanical adjuster: A screw located directly below the center of
the meter scale. The mechanical adjuster is used to set the meter
pointer to the Zero mark at the left side of the black scale.
Power supply: One 1.5V, size “AA” cell battery for Ohmmeter.
Size & Weight (with protective boot): 88mm x 155 mm x 49 mm, 288 g.
SAFETY PRECAUTIONS
1. Always visually inspect the multimeter, test leads, and circuit under
test for damage prior to every use.
2. Turn off power and discharge any capacitors and inductors prior to
connecting or removing test leads from an electrical circuit or electronic equipment.
3. Always keep yourself isolated from an electrical circuit when making
measurements. When possible use one hand to make measurements.
4. Never allow yourself to be grounded when making electrical measurements. Stand on a rubber mat, wear dry clothing, use insulated
test probes, and be careful of all exposed metal when making electrical measurements.
5. Never hold multimeter when making electrical measurements. Place
the multimeter on a clean insulated surface before making any electrical measurements.
OPERATING INSTRUCTIONS
CAUTION ! When making voltage or current measurements, form the
habit of turning off all power to the circuit under test, and discharge
any capacitors and inductors. Connect the test leads at the desired
points in the circuit and then turn on the power while taking readings.
Turn off the power and discharge any capacitors and inductors, before disconnecting the test leads from the circuit.
PRELIMINARY ADJUSTMENTS
Adjust the meter pointer to the Zero mark at the left side of the black
scale before making any measurements. First, check to see if the meter
pointer indicates Zero at the extreme left end of the black scale. If it is
off-Zero, use a small screwdriver to turn the mechanical adjuster screw
on the meter movement slowly CW (clockwise) or CCW (counterclockwise) until the meter pointer is exactly over the Zero mark.
INTERNAL BATTERY CHECK
Important: A 1.5V “AA” cell battery must be installed before using
the CP7849. (See Battery Replacement)
In order to check the battery condition, set the function range switch to
the RX10 position and touch the ends of the two test leads together.
Rotate the Zero Adjuster thumbwheel located on the left side of the
multimeter until the pointer indicates Zero on the green OHMS scale. If
the pointer cannot be brought to the Zero mark, replace the 1.5 volt size
“AA” cell battery. (See Battery Replacement)
OPERATING SUGGESTIONS
1. Set the range switch to the proper position before taking any measurement.
2. Never apply more voltage or current than the amount noted in each
position.
3. When the voltage or current to be measured is not known, always
start with the highest range in each case.
4. If the meter pointer is in the lower half of the scale and falls within
the range of a lower function range switch position, then rotate the
function range switch to the lower range for greatest accuracy.
5. If none of the multimeter functions work at all, check the fuse located inside the multimeter on the printed circuit board. If the fuse is
blown, replace it. (See Fuse Replacement)
6. Avoid placing the multimeter in a place where severe vibration is
encountered. Do not store it in excessively hot or damp places!
7. Do not check resistance when voltage or current is present in the
circuit.
8. Discharge a capacitor before measuring it.
9. When the multimeter is not in use, keep the function range switch in
the “OFF” position. This provides a direct short across the meter
movement, stabilizing the needle for minimum needle bounce when
transporting the multimeter.
10.
If excessive voltage or current is accidentally applied on a certain
range, disconnect the leads from the circuit as quickly as possible.
Check the multimeter operation on that range by applying an appropriate input. If the multimeter does not operate properly, check the
fuse; if it is blown, replace it. (See Fuse Replacement)
OPERATING PROCEDURES
DC VOLTAGE MEASUREMENT
1. Read all SAFETY PRECAUTIONS.
2. Set the function range switch to the appropriate DC voltage range. If
the voltage is unknown, use the highest range.
3. If the polarity of the circuit to be tested is known, connect the BLACK
probe to the (-) negative voltage side of the circuit, and the RED
probe to the (+) positive voltage side.
4. If the polarity of the circuit to be tested is not known, connect the
probes to opposite sides of the circuit and watch the meter pointer. If
the meter pointer deflects to the left, reverse the probes. The RED
probe will now be connected to the (+) positive voltage side.
5. Use the black scale for reading DC voltage measurements.
DC CURRENT MEASUREMENT
1. Read all SAFETY PRECAUTIONS.
2. Set the function range switch to the appropriate DC mA range. If the
current is unknown, use the highest range.
3.
Using the test leads, connect the multimeter in series with the circuit
under test. If the meter pointer deflects to the left, reverse the test probes.
4. Use the black scale for reading DC mA measurements.
AC VOLTAGE MEASUREMENT
1. Read all SAFETY PRECAUTIONS.
2. Set the function range switch to the appropriate AC voltage range. If
the voltage is unknown, use the highest range.
3. Connect the RED and BLACK test probes to opposite sides of the AC
voltage source. (Polarity of test probes is not important when measuring AC voltage.)
4. Use the red scale for 10V AC voltage measurements. Use the black
scale for 50V and 500V AC voltage measurements.
DECIBEL
1. Read all SAFETY PRECAUTIONS.
2. Set the function range switch to the appropriate AC voltage range for
the dB range you wish to measure.
3. For a function range switch setting of 10 AC V, read the dB directly
from the bottom red scale. For other AC V settings of the function
range switch, add the appropriate number of dB to the dB scale reading as noted on the chart at the lower right corner of the meter face.
RESISTANCE MEASUREMENT
1. Read all SAFETY PRECAUTIONS.
2. Turn off all power in circuit before making resistance measurements.
3. Set the function range switch to the appropriate OHM range. If the
resistance is unknown, use the highest range.
4. Touch the ends of the two test leads together. Rotate the Zero Adjuster thumbwheel located on the left side of the multimeter until the
pointer indicates Zero on the green OHMS scale. If the pointer cannot be brought to the Zero mark, replace the 1.5 volt size “AA” cell
battery. (See Battery Replacement)
5. Connect the test probes across the resistance to be measured.
6. Take a reading on the green OHMS scale and multiply it by the multiplication factor indicated by the function range switch. Multiply read-
ing by 1K (1000
switch position. The units for the RX10 position are Ohms “
7. If there is little or no meter pointer movement from the left side of
the green OHMS scale, rotate the function range switch to a higher
range in an effort to get a greater deflection of the meter pointer. The
) for the RX1K position and, by 10 for the RX10
”.
most accurate reading on an ohmmeter ranges between the middle
of the scale and Zero Ohms.
BATTERY CHECK
1. Read all SAFETY PRECAUTIONS.
2. Set the selector switch to the appropriate BAT range.
3. Touch and hold the RED test lead to the (+) positive battery terminal
and the BLACK test lead to the (-) negative battery terminal.
4. Read the BAT scale to determine the battery condition. If the reading
is in the red “BAD” zone, the battery should be replaced. If the reading is in the green “GOOD” zone, the battery has considerable life
left. If the reading is in the “?” zone, the battery should be replaced
soon because the remaining power is very low.
MAINTENANCE
GENERAL
1. No periodic maintenance is required other than replacement of the
battery, fuse, and visual inspection of the multimeter.
2. Keep the instrument clean and dry. Do not use solvent for cleaning;
use a damp cloth.
3. The only field replaceable parts are the 1.5V “AA” cell battery and the
Fast-Acting 5mm X 20mm, 500mA, 250V fuse.
BATTERY REPLACEMENT
Important: A 1.5V “AA” cell battery must be installed before using
the CP7849.
1. Rotate the function range switch to the OFF position.
2. Remove protective boot.
3. Remove screws from rear of multimeter and lift off the back cover.
4. Install a new 1.5V “AA” cell battery. Observe the polarity marks.
5. Carefully replace the back cover and tighten the screws. Be careful
not to over tighten the screws, because the threads in the case may
become stripped.
6. Replace protective boot.
FUSE REPLACEMENT
Important: If the multimeter won’t work at all, check the fuse located
inside the multimeter. If the fuse is blown, all functions stop working.
1. Rotate the function range switch to the OFF position.
2. Remove protective boot.
3. Remove screws from rear of multimeter, and lift off the back cover.
4. Replace blown fuse with a new Fast-Acting 5mm X 20mm, 500mA,
250V fuse.
5. Carefully replace the back cover and tighten the screws. Be careful
not to over tighten the screws, because the threads in the case may
become stripped.
6. Replace protective boot.
Made in China
FULL ONE (1) YEAR WARRANTY
Actron Manufacturing Company, 15825 Industrial Parkway, Cleveland, Ohio 44135, warrants to the
user that this unit will be free from defects in materials and workmanship for a period of one (1)
year from the date of original purchase. Any unit that fails within this period will be repaired without
charge when returned to the Factory. Actron requests that a copy of the original, dated sales receipt
be returned with the unit to determine if the warranty period is still in effect. This warranty does not
apply to damages caused by accident, alterations, or improper or unreasonable use. Expendable
items, such as batteries, fuses, lamp bulbs, flash tubes also are excluded from the scope of this
warranty. ACTRON MANUFACTURING COMPANY DISCLAIMS ANY LIABILITY FOR INCIDENTAL OR
CONSEQUENTIAL DAMAGES FOR BREACH OF ANY WRITTEN WARRANTY ON THE UNIT. Some
states do not allow the disclaimer of liability for incidental or consequential damages, so the above
disclaimer may not apply to you. This warranty gives specific legal rights, and you may also have
rights which vary from state to state.