11
The DC µA input terminal is protected by a 1.5K PTC (600V rating) thermistor
.
To avoid possible damage to the meter or to the equipment under test,
check the meter’s fuses before measuring current.
Use the proper terminals,
function, and
range for your measurement.
Never place the probes across (in parallel with) any circuit or component
when the leads are plugged into the current terminals
.
When measuring current, the meter acts like an impedance such as 0.01
Ω
at
AC/DC A (approximately 1.5K
Ω
at DC µA) in series with the circuit.
This loading effect of the meter can cause measurement errors,
loading effect
error
, especially in low impedance circuits.
For example : To measure a 1
Ω
impedance circuit will cause a –1% measuring
error. The
error percentage of the loading effect
of the meter is expressed as
following :
-
0.01
Ω
Zc
%
100
x
or
- E
Burden
E
S
%
100 x
E
S
I
m
Z
Circuit
E
Burden
AMMETER SHUNT
Caution
Making Basic Measurements
