19
Table 2-2.Range No., Range Resistance and Range Adjustment
From Table 2-2, there is a cross of 5% between two neighboring ranges, instead
of an absolute dividing limit. And the cross can avoid range’s frequent
jumpiness when the impedance is right at the dividing limit, and the range
doesn’t vary. For example, Zx = 920 k
Ω
, it will be measured in Range 2 or
Range 3.
According the test frequency, capacitance, or inductance, the range of the
capacitor or the inductor can be calculated.
For example: C = 0.22 µF, D = 0.0010, measurement frequency f = 10 kHz,
then
Ω
=
×
×
×
×
=
≈
+
=
−
37
.
72
10
22
.
0
10
10
2
1
2
1
2
1
6
3
π
π
π
X
X
X
X
X
fC
Z
fC
j
R
Z
From Table 2-3, the optimum range of this capacitor is Range 4.
2.2.5.2 Range Hold
When the components to be measured have the same nominal, we can set the
range mode to HOLD to increase the measurement speed. When in HOLD mode,
the instrument will not spend any time selecting the range. Perform the
following steps to select the optimum range:
1. Press
＜
or
＞
key to select the function of RANGE;
2. Make sure that the range mode is in AUTO state;
3. Connect one of the components to the fixture;
4. Set the range mode to HOLD using
∧
or
∨
key after the measurement value
is stable.
If the impedance of DUT is out of the effective measurement range of the held
range, TH2810B’s measurement accuracy does not meet its specification. So
make sure that the optimum range is selected when using the range hold
function.
2.2.6 Measurement speed
TH2810B provides two measurement speeds: fast and slow. When the range is
set to AUTO, measurement time needs to increase range adjustment time, and
when the range is not correct, range adjustment time and another
measurement time need to be increased.
Measurement Time
The measurement time consists of two main parts: integration time and
calculation time.
The sum of integration time and calculation time determine the measurement
speed.
The calculation time is about 25 ms;
