Showa 5683, Руководство по эксплуатации

Страница: 44 / 68

４−１０
(2) Measurement with various types of transducers
This calibration voltage value is linked with the bridge supply voltage, and the amount of
calibration can always be applied with any panel-indicated value (1
µ
ε to 9,999
µ
ε ).
Example:
If a load cell with a rated capacity and a rated output of 1 kN and
１
mV/V is used, to convert
the rated output of １ mV/V into an amount of strain, the rated output is given by:
1mV/V X 2V = 2mV
Where the load cell is used with the bridge voltage (E) = 2V.
If the measurement is based on the quarter-bridge configuration with a gate factor (K) of 2.00,
the relationship between the amount of strain (
ε
) to be applied to the bridge and the output
voltage (e) is given by:
e = 1/4 x
Ｋ
x
Ｅ
x
ε
= 1/4 x 2 x 2 x
ε
=
ε
That is, 1
µ
ε strain corresponds to 1
µ
V and 1000
µ
ε to 1 mV. The rated output of 2 mV
corresponds to 2000
µ
ε . As a result, the relationship between calibration values and the physical
amount is as follows irrespective of the bridge supply voltage:
Calibration Strain Calibration Physical Amount
2000×10 ｰ
6
strain 1kN×1 = 1kN
1000×10 ｰ
6
strain 1kN×1/2 = 500N
500×10 ｰ
6
strain 1kN×1/4 = 250N
200×10 ｰ
6
strain 1kN×1/10 = 100N
Table4-6
The formula is as follows:
Calibration value of physical amount = x Rated capacity
The physical amount can be calculated as follows:
Calibration value of physical amount: 250 N (500
µ
ε ）
Deflection of CAL waveform: 10 mm
Deflection at point
Ｂ : 22 mm
The physical amount can be calculated as follows:
Load at point
Ｂ
= x 250 N = 550 N
4.4.1 Correction of Calibration (CAL) Values
(1) Where gauge factors are not 2.00
In this amplifier unit, its gauge factor is set to 2.00. If strain gauges with a gauge factor other
than 2.00 are to be used, the following formula must be used.
True CAL value = x CAL value of unit
(2) Where bridge configurations are not quarter-bridge configuration
The calibration (CAL) values of this amplifier unit are equivalent voltage values based on the
Calibration value for 10
-6
strain of the amplifier
Rated output value (10
-6
strain)
22
10
2.00
Kc (Gauge factor of strain gauge)