Azbil VDC User Manual

Operation using the data setting device Azbil Corporation
5-52 Model MTG11A/18A, MTG11B/18B, MTG14C
2. DUTY 50% (Automatically set)
Selecting DUTY 50% automatically sets the pulse width as follows:
Calculation method 1
Make calculations to obtain a pulse width that is DUTY 50% of the span
frequency. The pulse width is automatically set. In this case, the calculated
value of the pulse width does not appear on the display.
Calculation method 2
In addition, if the pulse width calculated by the calculation method 1 exceeds 1
second, the pulse width is set to 1 second.
Calculation method 1: When the range is 360 m
3
/h, and pulse scale is 2 l/P,
First convert the unit of range to calculate the span frequency.
Convert the range into the unit of per-second (/s).
360 m
3
/h  0.1 m
3
/s
Convert the unit of flow rate range to be same as the unit of pulse scale.
0.1 m
3
/s  0.1 × 1000 l/s
100 l/s
Calculation of span frequency
(100 l/s) / (2 l/P)
= 50 Hz
50 Hz  20 ms (= A)
Calculation of pulse width where the DUTY ratio is equivalent to 50%
B = 0.5 × A
= 0.5 × 20 ms
= 10 ms
Therefore, the pulse width is 10 ms.
Calculation method 2: When the range is 36 m
3
/h, and pulse scale is 100 l/P,
First convert the unit of range to calculate the span frequency.
Convert the range into the unit of per-second (/s).
36 m
3
/h  0.01 m
3
/s
Convert the unit of flow rate range to be same as unit of pulse scale.
0.01m
3
/s  0.01 × 1000 l/s
10 l/s
Calculation of span frequency
(10 l/s) / (100 l/p)
= 0.1 Hz
0.1 Hz  10 s (= A)
Calculation of pulse width where the DUTY ratio is equivalent to 50%
B = 0.5 × A
= 0.5 × 10 s
= 5 s
Because the calculated pulse width exceeds 1 s, it takes 1s.
CM2-MTG300-2001.book 52 ページ ２０１５年９月２９日 火曜日 午前１０時１４分

Azbil VDC Specifications

General

Brand	Azbil
Model	VDC
Category	Measuring Instruments
Language	English