YOKOGAWA EJX530A - Page 45

<8. Maintenance>
8-2
IM 01C25F01-01E
Table 8.1 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 mmH2O}
Accuracy:±0.05%ofF.S.
Requires air pressure
supply.
Dead weight gauge tester 25 kPa {2500 mmH2O}
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difcultiesincalibrationtothislevelintheeld.Forcalibrationtothe0.1%orhigherlevel,useproper
instruments for required level or contact Yokogawa representatives from which the instrument was purchased or the nearest
Yokogawaofce.
P
If a pressure generator
is used:
Reference pressure
Supply pressure
Model 7674 pneumatic
pressure standards
V
RRc
Load resistance,
250Ω
Load
adjustment
resistance,
100Ω
Digital voltmeter
Power
supply
E
If a pressure source and
a manometer are combined:
Model MT220
precision digital manometer
F0801.ai
Reference pressure
Pressure source
V
RRc
Load resistance,
250Ω
Load
adjustment
resistance,
100Ω
Digital voltmeter
Power
supply
E
P
Figure 8.1 Instrument Connections (4 to 20 mA output)