YOKOGAWA DT450G Series, User Manual, Page: 31 / 41

<4. Operation>
4-4
IM 11K01C01-01E
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Setting Alarm Contacts
Press the leftmost (A) key until the leftmost digit shows “1” or “2”. Set the alarm contact of relay
1 or 2 in percent of the output full scale value. Each press of the middle (B) or the rightmost (C)
key only increases the number, which will roll back to 1% after it reaches 99%. The percentage is
displayed by the two rightmost display digits.
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Trimming Analog Output Signals (4 mA and 20 mA)
Press the leftmost (A) key until the leftmost digit shows “3” or “4”. Increase or decrease the
output current. The display shows the nominal mA value with its two rightmost digits. Connect
a calibrated mA meter to the analog output terminal to check the actual current value. Allow 30
minutes warm up time before trimming the mA output.
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Setting Time Constants
Press the leftmost (A) key until the leftmost digit shows “5” or “6”. Change the time constant of the
alarm contact or the analog output signal in increments of 10 seconds.
The alarm contact time constant will change back to 0 s from 180 s, the analog output signal
time constant from 300 s. The two leftmost digits of the value are displayed by the two rightmost
display digits.
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Setting of the Measuring Range
The measuring range can be set manually or by Auto Setup button.
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Manual Setting
In manual setting the measuring range is set by amplifying the signal detected by the sensor in 5
stages.
Press the leftmost (A) key until the leftmost digit shows “1.0”, and press the middle (B) or the
rightmost (C) key until the rightmost digit shows the number of the desired parameter. Table 4-2
shows that the rightmost digit number and its parameter.
Table 4-2 Measuring Range Setting
Display
Right Number
Parameter Description
0
1
2
3
4
5
Automatic range setup
Maximum range (For high concentration of dust)
Gain x 10
Gain x 100
Gain x 1000
Gain x 10000 (For low concentration of dust)
When parameter 1 is selected, the measuring range is maximized. If the dust concentration is
high, select this parameter. The output sensitivity becomes higher as the parameter number
increases from “1” to “5”. Chose the most appropriate parameter for your process.
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Auto Setup
In the process where the dust concentration is a certain level and stable during normal operation,
range setting by Auto Setup button is also available.
Before the Auto Setup, the setting level should be confirmed.
The dust monitor has an Automatic Setup function. You can change the default percent of full
range (20%) in steps of 10% from 10 to 50%. Press the leftmost (A) key until the leftmost digit
shows “7” and increase or decrease the value using the middle (B) or the rightmost (C) key.