SMC Networks PF3A-H Series Manual page 26

PF3A H(-L)
w
IN Side Straight Section and Accuracy (Reference Data)
PF3A703H(-L) (for 3000 L/min)
±70%
With ø1/2" connected
±60%
±50%
±40%
With ø3/4" connected
±30%
±20%
Elbow piping (1")
±10%
±3%
0%
0 1 2 3 4 5
Straight section [d]
· Do not connect equipment or piping which may generate fluctuations in the flow or
drift on the IN side of the product. When installing a regulator on the IN side of the
product, make sure that chatter is not generated.
· The piping on the IN side must have a straight section of piping whose length is more
than 8 times the piping I.D.
If a straight section of piping is not installed, the accuracy may vary by ±3% F.S. or more.
* The "straight section" refers to a section of piping without any bends or rapid
changes in the cross sectional area.
Temperature Accuracy (Reference Data)
PF3A801H/802H-L
+7.5
+5
+2.5
0
−2.5
−5
0 A
Model A
PF3A801H-L
100 L/min
PF3A802H-L
200 L/min
< Temperature Measurement >
When there is no (low) fluid flow, the heat of the platinum sensor heated for flow detection is transmitted to the
temperature sensor, so the temperature measurement value in the low flow range (less than 1 0 % of the rated
flow rate) tends to increase in relation to the fluid temperature.
< Detection Principle (Flow) >
When a heated platinum sensor is installed in the branch passage, and fluid flows through it, the fluid removes
heat from the platinum sensor. The resistance value of the platinum sensor decreases as it loses heat. As the
resistance value decrease ratio has a uniform relationship to the fluid flow, the flow rate can be detected by
measuring the resistance value.
25
Series
PF3A706H(-L) (for 6000 L/min)
±70%
±60%
±50%
±40%
±30%
±20%
±10%
±3%
0%
6 7 8 0 1
Measurable within this range
Flow rate [L/min]
B
1000 L/min
2000 L/min
With ø1" connected
With ø1 1/4" connected
Elbow piping (1 1/2")
2 3 4 5 6 7 8
Straight section [d]
When piping with a diameter
smaller than the straight
section is connected
Elbow piping
B
PF3A712H(-L) (for 12000 L/min)
±70%
With ø1 1/4" connected
±60%
±50%
±40%
With ø1 1/2" connected
±30%
Elbow piping (2")
±20%
±10%
±3%
0%
0 1 2 3 4
Straight section [d]
Straight
section
IN
When piping of a different diameter is connected to the IN port
Straight
section
IN
When elbow piping is connected to the IN port
5 6 7 8
OUT
OUT