Yokogawa EJA530A User Manual

Page 51

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IM 01C21F01-01E

9-2

9. MAINTENANCE

Table 9.2.1 Instruments Required for Calibration

Name

Remarks

Yokogawa-recommended Instrument

Power

supply

Model SDBT or SDBS distributor

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.)

±(0.2% of rdg + 0.1% of F.S.)

2) For 130 kPa class

Accuracy: ±0.02% of rdg

±5digits
±(0.2% of rdg + 0.1% of F.S.)

3) For 700 kPa class

Accuracy: ±(0.02% of rdg + 3digits)

±5 digits
±(0.2% of rdg + 0.1% of F.S.)

4) For 3000 kPa class

Accuracy: ±(0.02% of rdg + 10 digits)

±(0.2% of rdg + 0.1% of F.S.)

5) For 130 kPa abs class

Accuracy: ±(0.03% of rdg + 6 digits)

4 to 20 mA DC signal

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.

Pressure

source

Model 6919 pressure regulator (pressure pump)

Pressure range: 0 to 133 kPa {1000 mmHg}

Prepare the vacuum pump
for negative pressure
ranges.

Dead weight gauge tester 25 kPa {2500mmH

2

O}

Accuracy: ±0.03% of setting

Select the one having a
pressure range close to
that of the transmitter.

T0901.EPS

for 0 to 10 kPa
for -10 to 0 kPa

for 25 to 130 kPa
for 0 to 25 kPa
for -80 to 0 kPa

for 100 to 700 kPa
for 0 to 100 kPa
for -80 to 0 kPa

for 0 to 3000 kPa
for -80 to 0 kPa

for 0 to 130 kPa abs

. . . . .

. . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . .

. . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . .

. . . . . . . . . . .

. . . . . . . . .

. . . . . . . . . . . .

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% level, there are
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

If a pressure generator
is used:

Reference pressure

Supply pressure

Model 7674 pneumatic
pressure standards

V

R

Rc

Load resistance,

250 Ω

Load
adjustment
resistance,
100 Ω

Digital voltmeter

Power
supply
E

If a pressure source and
a manometer are combined:

Model MT220
precision digital manometer

F0901.EPS

Reference pressure

Pressure source

V

R

Rc

Load resistance,

250 Ω

Load
adjustment
resistance,
100 Ω

Digital voltmeter

Power
supply
E

P

Figure 9.3.1 Instrument Connections

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