6
All Rights Reserved. Copyright © 1999, Yokogawa M&C Corporation
IM 77J01S07-01E
11. MAINTENANCE
The product starts running immediately when the power is turned on;
however, it needs 10 to 15 minutes of warm-up before it meets the
specified performance.
For cleaning the instrument, use a soft and dry cloth.
11.1 Calibration Apparatus
●
Two 6 dial variable resistors (Yokogawa M&C 2793 01 or the
equivalent)
●
A voltmeter (Yokogawa 7562 or the equivalent)
●
A precision resistor of 250
Ω
±
0.01%, 1W (for current output)
11.2 Calibration Procedure
Connect the instruments as shown in Fig. 11.1. First adjust Out-
put-1 signal and then Output-2 signal.
Operate the variable resistor according to the specifications (full
resistance, 0%, 100% resistance) of the potentiometer to be con-
nected. Change the values of R1 and R2 on keeping the full resis-
tance fixed, and then produce input signals equivalent to 0, 25, 50,
75, and 100% of the input span to the transmitter. Check that the
transmitter’s output signal shows voltages corresponding to 0, 25,
50, 75, and 100% of the input span within the rated accuracy
range.
If the output signal is out of the rated accuracy range, adjust the
output signal level using a PC (VJ77 PC-based parameters setting
tools) or the Handy Terminal (JHT200). For information on ad-
justment, refer to the Instruction Manual for VJ77 PC-based Pa-
rameters Setting Tool (IM 77J01J77-01E) or the Instruction
Manual for JHT200 Handy Terminal (IM JF81-02E).
10
11
3
2
1
4
5
6
7
8
9
100%
0%
R1
R1
R2
R2
Input signal
9
7
Analog output
Output-1 signal
Voltmeter
R
R: For current output using 250
Ω
precision resistor
+
–
3
1
4
6 dial
variable
resistor
6 dial
variable
resistor
5
2
Analog output
Output-2 signal
Voltmeter
R
R: For current output using 250
Ω
precision resistor
+
–
Power supply
11
10
8
L+
N–
GND
Fig. 11.1
