UEi Test Instruments MCP9A - Manual (Page 3)

M a i n t e n a n c e
Periodic Service
WARNING!
Repair and service of this instrument is to be performed by qualified
personnel only. Improper repair or service could result in physical
degradation of the meter. This could alter the protection from
electrical shock and personal injury this meter provides to the
operator. Perform only those maintenance tasks that you are
qualified to do.
These guidelines will help you attain long and reliable service from
your meter:
• Calibrate your meter annually to ensure it meets original
performance specifications
• Keep your meter dry. If it gets wet, wipe dry immediately.
Liquids can degrade electronic circuits
• Whenever practical, keep the meter away from dust and dirt
that can cause premature wear
• Although your meter is built to withstand the rigors of daily use,
it can be damaged by severe impacts. Use reasonable caution
when using and storing the meter
Cleaning
Periodically clean your meter’s case using a damp cloth. DO NOT use
abrasive, flammable liquids, cleaning solvents, or strong detergents as
they may damage the finish, impair safety, or affect the reliability of the
structural components.
Clean the input terminals as follows:
1. Turn the meter off and remove all test leads.
2. Shake out any dirt that may be in the terminals.
3. Soak a new swab with alcohol and work the swab around in
each terminal.
Battery Replacement
The purpose of the internal 1.5 V, size “AA”, battery is to supply power
tot he circuit under test while making resistance measurements.
Eventually the battery will age to the point where it will not be possible
to zero the meter with the “OHM ADJ” control. When this happens the
battery should be replaced.
Observe the proper battery polarity when replacing the battery. It is
recommended that the battery be removed if the MCP9A is not to be
used for a long period of time. Remove the screws in the rear of the
case for access to the battery.
WARNING!
Disconnect the test leads from the circuit under test and from the meter
prior to removing or installing batteries.
WARNING!
Under no circumstances should you expose batteries to extreme heat or
fire as they may explode and cause injury.
Operating Instructions
Measuring AC Current
When measuring current, always be sure the “SEL ECTOR” switch is set
to the appropriate AMP range. When in doubt, always use the highest
current range first. The switch can always be reset to a lower range for a
more precise reading. AC current measurements are made on the black
A MP sca l e s .
Clamp the jaw the MCP9A around a single circuit wire.
NOTE: Clamp only one wire at a time for measurement. If two or more
wires are clamped together, the tester will not read.
If the measured value on the meter scale is less than the full scale value
of the next lower range, reset the “SEL ECTOR” switch to the lower ra n g e
for a more accurate reading.
Slide P OINTER LOCK switch toward the right to lock the pointer at its
i n d i cating point when readings must be made in a confined or difficult-to-
read loca t i o n .
Measuring AC Voltage
When measuring voltage be sure the “SEL ECTOR” switch is set to the
appropriate Volt range. When in doubt, always use the highest Volt ra n g e
first. The switch can always be set to a lower range for a more precise
reading. AC voltage measurements are made on the red Volt sca l e s .
Insert the red and black test leads into the “C OM” and “VOLT” input
jacks. The test leads may be locked in position by rotating them to the
right (clockwise). Connect the two test leads to the circuit under test.
Measuring Resistance
WARNING!
Remove all power to the circuit under test when making resistance
measurements. If any voltage is present in the test circuit an erroneous
reading will result and the MCP9A fuse may open.
Connect the black test lead to the “COM” jack and the green test lead
to the “OHMS” jack. The “OHMS” jack has an internal switch so be
sure that the green test lead is inserted fully into the jack.
Touch the free ends of the test leads together. The pointer will swing to
the right hand side of the scale. Adjust the “OHM ADJ” control until the
pointer is set on the green numeral 0.
NOTE: If this adjustment cannot be made refer to the “MAINTENANCE”
section. Re-zero the MCP9A each time that the tester is used for making
resistance measurements.
To make the resistance measurement, connect the free ends of the test
leads across the element to be measured. The measured resistance
value will be the green numeral indicated on the “OHMS” scale.
MCP9A-MAN P. 2