Amprobe MO-100 Milliohm-Meter - Manual (Page 8)

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INTRODUCTION
• The Milliohm Meter is a battery operated instrument wich supply
a low current to the circuit under test, with which, stable, accurate
measurement of low resistance can be made, still, over a wide range of
values.
• Resolution on the lowest range is 100μ ohm and on the highest range,
1 ohm.
• The meter has 5 measuring ranges, from 200.0 milli-ohm to 2000 ohms
• Measurements are displayed on a 3½ digit custom liquid crystal display
with large digits.
• This instrument is powered from batteries only (alkaline or rechargeable
equivalent).
• It has a regulated DC constant current source with current of 1mA 10mA
and 100mA.
• The instrument supply that current to the resistance being measured
through the C1 and C2 terminals (C1 being +, C2 being -).
• The voltage drop across the resistance under test is measured by the
potential terminals P1 and P2 (P1 being +, P2 being -).
• Should the current regulation drops out, the Rc LED will lit, indicating
that the resistance in the current circuit is too high. (Lowering the
current by selecting a higher resistance range can solve the regulation.)
• Should the Rp LED lit, that mean that the voltage measured on the
resistance is too high, and therefore over-range.
• The resistance is measured precisely when the RP and RC LEDs do not lit.
If anyone of these leds lit, then the measurement can be inaccurate.
• The meter has a built-in custom 3½ digit liquid crystal display can
be viewed in most lightning conditions. This display indicates the
differences conditions (Hold, m, buzzer, polarity condition of load, + or -,
automatic decimal point change).
• The instrument takes measurements for 10 seconds if the “ON” “TEST
Re button is depressed for less than 2 seconds. If the same push button is
pressed for more than 3 seconds, the test will carry on for 60 seconds.
• The tester switch “OFF” completely when the rotary switch is in the
“OFF” position.
• The tester “Hold” the last reading before stopping the test.
• The tester is fuse protected and has a crowbar between C1 and C2.