Brochure
26
Parts Description
Construction
Detection Principle
2
IN
1
S
Output (OUT1)
indicator
Output (OUT2)
indicator
Button
Button
Button
LED display
Flow
adjustment
valve
Knurled
lock
nut
Piping port
Body
Through-hole
This MEMS sensor chip consists of upstream temperature measuring sensor (Ru) and
downstream temperature measuring
sensor (Rd), which are placed symmetrically from the
centre of a platinum thin film coated heater (Rh) mounted on a membrane, and an ambient
temperature sensor (Ra) for measuring gas temperature.
The principle is as shown in the diagram on the right. (a) When the gas is static, the tempera-
ture distribution of heated gas centered around Rh is uniform, and Ru and Rd have the same
resistance. (b) When the gas flows from the left side, it upsets the balance of the temperature
distribution of heated gas, and the resistance of Rd becomes greater than that of Ru.
The difference in resistance between Ru and Rd is proportional to the gas velocity, so mea-
surement and analysis of the resistance can show the flow direction and velocity of the gas.
Ra is used to compensate the gas and/or ambient temperature.
Ra
Ru Rh Rd
Ra
Ru Rh Rd
Flow
(b) The gas flows from the left side.
(a) The gas is static.
Component Parts
!1
!5
!2
!3
!6
!7
!4
q w
w
q o ire uy!0 o
t
PFM7
PFM5
Illuminates when the output (OUT1) is turned on.
Flashes when overcurrent error occurs.
Description
Output (OUT1)
indicator (Green)
Item
Illuminates when the output (OUT2) is turned on.
Flashes when overcurrent error occurs.
Output (OUT2)
indicator (Red)
Indicates the flow rate, set mode state and error code. The display colour can
be selected between red and green according to the output (OUT1) status.
LED display
Selects the operation mode and increases the set value for ON and OFF.
Used to transfer to peak indication mode.
Selects the operation mode and decreases the set value for ON and OFF.
Used to transfer to bottom indication mode.
Used to make changes in each mode and to enter the set value.
Reset function is activated by pressing
and buttons simultaneously.
Returns the indicated value to zero and clears errors.
Flashing interval changes according to flow rate. Flashes faster when flow
rate is increased. Colour changes to red when exceeding the rated flow rate.
Reset
Main body of the flow switch
Body
Orifice mechanism to adjust the flow rate
Flow adjustment valve
Connection port for piping
Piping port
Flow rate confirmation
indicator (Green)
Used to fix the needle.
Knurled lock nut
Illuminates when power is supplied.
Power confirmation
indicator (Green)
Button
Button
Button
Flow rate confirmation
indicator (Green)
Power confirmation
indicator (Green)
Fitting for piping
O-ring
O-ring
Rectifying module
Body
Sensor housing
Sensor chip
Orifice
Seal
Mesh
Bottom piping adapter
O-ring
Flow adjustment valve
assembly
Body
B
Needle
O-ring
O-ring
No. Description Note
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Electroless nickel plated
Fluoro coated
Fluoro coated
Electroless nickel plated
Fluoro coated
Fluoro coated
Electroless nickel plated
Electroless nickel plated
Fluoro coated
Fluoro coated
Material
Brass
FKM
HNBR
PBT
LCP
Silicon
Brass
FKM
PBT
HNBR
PBT
Brass
Brass
HNBR
HNBR
Stainless
steel 304
Stainless
steel 304
2-Colour Display Digital Flow Switch
Series PFM7/PFM5
Pressure Loss (Pressure: 350 [kPa])
Flow Characteristics
PFM710, 510 / For 10 (l/min)
Pressure loss (kPa)
0.35
0.30
0.25
0.20
0.15
0.10
0.05
Flow rate (
l
/min)
1 2
4 6 8 1
0
0
PFM750, 550
/ For 50 (l/min)
Pressure loss (kPa)
4
3
2
1
Flow rate (
l
/min)
5 10 20 30 40 500
PFM711, 511
/ For 100 (l/min)
PFM725, 525 / For 25 (l/min)
Pressure loss (kPa)
1.0
0.8
0.6
0.4
0.2
Flow rate (
l
/min)
5 1
0 1
5 2
0 2
5
0
Pressure loss (kPa)
14
12
10
8
6
4
2
Flow rate (
l
/min)
10 20 40 60 80 1000
PFM725, 525
/ For 25 (l/min)
PFM711, 511
/ For 100 (l/min)
Series PFM7/PFM5
Common Specifications
PFM710, 510
/ For 10 (l/min)
PFM750, 550
/ For 50 (l/min)
60
40
20
0
5 10 1
5
0
Flow rate (l/min)
Number of needle rotations
750 (kPa)
300 (kPa)
100 (kPa)
Flow rate (
l
/min)
Number of needle rotations
120
100
80
60
40
20
5 10 1
5
0
750 (kPa)
300 (kPa)
100 (kPa)
Flow rate (
l
/min)
Number of needle rotations
30
20
10
5 10 1
5
0
750 (kPa)
300 (kPa)
100 (kPa)
Flow rate (l/min)
Number of needle rotations
15
10
5
0
5 10 1
5
750 (kPa)
300 (kPa)
100 (kPa)