Yokogawa EJX118A - Manual (Page 37)

<8. Maintenance>
7-2
IM 01C25H01-01E
Table 7.1 Instruments Required for Calibration
Name Yokogawa-recommended Instrument Remarks
Power supply Model SDBT or SDBS distributor 4 to 20 mA DC signal
Load resistor Model 2792 standard resistor [250 Ω ±0.005%, 3 W]
Load adjustment resistor [100 Ω ±1%, 1 W]
Voltmeter Model 2501 A digital multimeter
Accuracy (10V DC range): ±(0.002% of rdg + 1 dgt)
Digital
manometer
Model MT220 precision digital manometer
1) For 10 kPa class
Accuracy: ±(0.015% of rdg + 0.015% of F.S.). . . . for 0 to 10 kPa
±(0.2% of rdg + 0.1% of F.S.). . . . . . . . for -10 to 0 kPa
2) For 130 kPa class
Accuracy: ±0.02% of rdg. . . . . . . . . . . . . . . . . . . . for 25 to 130 kPa
±5digits. . . . . . . . . . . . . . . . . . . . . . . . . for 0 to 25 kPa
±(0.2% of rdg + 0.1% of F.S.). . . . . . . . for -80 to 0 kPa
3) For 700 kPa class
Accuracy: ±(0.02% of rdg + 3digits) . . . . . . . . . . . for 100 to 700 kPa
±5 digits . . . . . . . . . . . . . . . . . . . . . . . . for 0 to 100 kPa
±(0.2% of rdg + 0.1% of F.S.). . . . . . . . for -80 to 0 kPa
4) For 3000 kPa class
Accuracy: ±(0.02% of rdg + 10 digits). . . . . . . . . . for 0 to 3000 kPa
±(0.2% of rdg + 0.1% of F.S.). . . . . . . . for -80 to 0 kPa
5) For 130 kPa abs class
Accuracy: ±(0.03% of rdg + 6 digits) . . . . . . . . . . . for 0 to 130 kPa abs
Select a manometer having
a pressure range close to
that of the transmitter.
Pressure
generator
Model 7674 pneumatic pressure standard for 200 kPa {2 kgf/cm 2 }, 25 kPa
{2500 mmH
2
O}
Accuracy: ±0.05% of F.S.
Requires air pressure
supply.
Dead weight gauge tester 25 kPa {2500 mmH 2 O}
Accuracy: ±0.03% of setting
Select the one having a
pressure range close to that
of the transmitter.
Pressure
source
Model 6919 pressure regulator (pressure pump)
Pressure range: 0 to 133 kPa {1000 mmHg}
Prepare the vacuum pump
for negative pressure
ranges.
Note: The above table contains the instruments capable of performing calibration to the 0.2% level. Since special maintenance and
management procedures involving traceability of each instrument to higher-level standards are required for calibration to the 0.1%
or higher level, there may be difficulties in calibration to this level in the field. For calibration to the 0.1% level, contact Yokogawa
representatives from which the instrument was purchased or the nearest Yokogawa office.
P
P
V
Mating calibration flange
Load resistance, 250Ω
Model MT220
precision digital manometer
High pressure side
diaphragm seal
Rc
R
Load adjustment
resistance, 100Ω
Digital voltmeter
Power
supply
E
Low pressure side diaphragm seal
Model 7674 pneumatic
pressure standards
Pressure source
Supply pressure
If a pressure
generator is used:
If a pressure source
and a manometer
are combined:
F0701.ai
Figure 7.1 Instrument Connections