10 TEGAM WAY • GENEVA, OHIO 44041 • 440-466-6100 • FAX 440-466-6110
3-2
OPERATING INSTRUCTIONS
3.2
General Theory Of Operation
Measurement Principle
A 4-terminal measurement method is used to determine the
resistance of the item under test. This method allows the
accurate measurement of low values of resistance in spite of
the other resistances present in the connection leads. A known
current is supplied to the item under test via two wire leads
connected to the +I and -I binding posts on the R1L-BI/R1L-
BIR Microohmmeter front panel. Two other wire leads
connected to the +E and -E binding posts on the R1L-BI/R1L-
BIR front panel sense the voltage developed across the
resistance under test due to the supplied known current. The
R1L-BI/R1L-BIR then calculates the resistance of the item
under test utilizing Ohm's law, and displays it on a 3 ½ digit
display.
Kelvin Klip Cable Description
A Kelvin clip consists of two opposing jaws of an alligator style
clip which are insulated from each other, so one jaw may be
used to connect a source of current to the resistance under
test, and the other jaw used to measure the voltage at the test
point. The two jaws are spring loaded to clamp onto a cylinder
of ½ inch diameter or less.
WARNING
OPERATING THE R1L-BI/R1L-BIR MICROOHMMETER AND
TAKING RESISTANCE MEASUREMENTS ON A POWERED OR
ENERGIZED COMPONENT COULD CAUSE SERIOUS HARM
TO THE OPERATOR AND/OR DAMAGE THE INSTRUMENT.
BE SURE THE ITEM TO BE MEASURED IS DISCONNECTED
FROM OTHER COMPONENTS AND APPARATUS.
If the battery cells have not been installed, refer to section
2.2. Battery only operation will result in the most stable and
accurate readings. The R1L-BI/R1L-BIR may be operated