IM 01C25R01-01E
9-2
9. MAINTENANCE
Table 9.1 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.
Variable
resistor
279301 type 6-dial variable resistor (accuracy:
±
0.005%)
For calibration of
thermometer resistor
(RTD) input
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.
T0901E.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% 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.
9.3.2 External Temperature (RTD)
Using a thermometer resistor as input, calibration of
the temperature transmitter is carried out via a 3-core
wire connection.
As defined the reference resistor value table of the
thermometer resistor (RTD), obtain resistance values
corresponding to 0, 25, 50, 75 or 100% of the span,
and use the obtained resistance as the input value, then
deliver it to the temperature transmitter by means of a
variable resistor. Measure the resulting output signal
with the voltmeter (digital multimeter) and check the
output value relative to the input value.
If the output signal deviates from the given range of
accuracy when a given input signal is delivered, adjust
the output using the handheld terminal. For details of
how to adjust the output, refer to the additional
references, “HART Protocol” IM 01C25R02-01E and
the instruction manual for each terminal.
