Series PF2
, IF
Diaphragm Style Flow Switch:
Series IFW
Paddle Style Flow Switch:
Series IF3
Flow Switches
Model Contacts Port size (Rc, NPT, G)
IFW510
IFW520
IFW550
Flow rate measuring range
(l/min)
1 to 10
10 to 20
20 to 50
1ab 3/8, 1/2, 3/4
Model Contacts Port size (Rc, NPT, G)
1F30
1F31
1F33
Flow rate measuring range
(l/min)
14 to 60
20 to 150
36 to 2600
1ab
3/4
1
1
Page
16-12-1
Page
16-12-6
Digital Flow Switch
Mechanical Flow Switch
Digital Flow Switch for Air:
Series PF2A
························································· Refer to page 16-11-7.
Digital Flow Switch for Water:
Series PF2W
··················································· Refer to page 16-11-17.
Digital Flow Switch for Deionized Water and Chemicals:
Series PF2D
······ Refer to page 16-11-37.
16-11-1
ZSE
ISE
PSE
Z
ISE3
PS
Z
ISE 1
2
ZSP
ISA2
IS
ZSM
PF2
IF
Data
Design and Selection Mounting
Thread
1/8
1/4
3/8
1/2
3/4
1
Proper tightening torque (N·m)
7 to 9
12 to 14
22 to 24
28 to 30
28 to 30
36 to 38
Flow Switches
Precautions 1
Be sure to read before handling.
1. Make sure to use a switch by the specified voltage.
Use of a switch outside the range of the specified voltage can
cause not only malfunction and damage of the switch, but
also electrocution and fire.
2. Never use such a load, which exceeds the
maximum allowable load.
It may result in a damage to a switch.
3. Since the type of fluid varies depending on the
product, make sure to verify the specifications.
Never use flammable gases or fluids, since the switch is not
explosion proof construction. It may result in a fire.
[For air]
4. Make sure to use a switch within the specified flow
rate for measurement and the maximum operating
pressure.
Operating beyond the specified flow rate and operating pressure
can damage the switch.
If using a switch by exceeding the maximum operating pressure,
switch is damaged.
[For water]
5. Make sure to use a switch within the specified flow
rate for measurement and the maximum operating
pressure.
Operating beyond the specified flow rate and operating
pressure can damage the switch.
Damage to the switch may occur if the switch is subject to
higher pressure than its designed limit.
Avoid especially the application of pressure above
specifications through a water hammer.
<Countermeasure examples>
a) Use a device such as a water hammer relief valve to slow
the valve's closing speed.
b) Absorb an impact pressure by using a rubber material
piping such as a rubber hose and an accumulator.
c) Keep the piping length as short as possible.
1. Mount a switch by observing the proper tightening
torque.
When a switch is tightened beyond the specified tightening
torque, a switch may be damaged. On the other hand,
tightening below the specified tightening torque may cause
the installation screws to come loose during operation.
2. Apply a wrench only to the metal part of the piping
when installing the flow switch in the system
piping.
Do not apply a wrench to the plastic part of the main housing
of the switch.
3. Monitor the flow direction of the fluid.
Install a switch in the direction as indicated on the body.
4. Remove solid foreign objects, etc. inside piping by
air blow before connecting a switch with piping.
5. Do not drop or bump.
Do not drop, bump, or apply excessive impacts (490 m/s2)
while handling. Although the external body of the switch
(switch case) may not be damaged, the inside of the switch
could be damaged and cause a malfunction.
6. Hold the body of a switch when handling.
The tensile strength of the cord is 49 N. Applying a greater
pulling force on it can cause a malfunction. When handling,
hold the body of the switch—do not dangle it from the cord.
7. Do not use until you can verify that equipment can
operate properly.
Verify whether it is mounted correctly by running fluids or
applying the electricity in order to conduct suitable function
and leakage tests when mounting for the first time or after
system repair or modification was made.
[For air]
8. Ever mount a switch in a place that will be used as
a scaffold during piping.
If an excessive weight is applied on a switch, switch may be
damaged.
9. Be sure to allow straight pipe length that is
minimum 8 times the port size upstream and
downstream of the switch piping.
Do not suddenly narrow the pipe size because doing so will
disturb the flow speed distribution in the pipe, making it
impossible to obtain the correct measurements.
[For water]
10. Never install a switch in such a place, where switch
is used as a foothold in the piping.
Damage may occur if an excessive load is applied to the
switch. Especially when the switch supports the piping, do not
apply a load of 15 N·m or more to the metal parts of the
switch.
Warning Warning
16-11-2
Operating Environment
Wiring
Maintenance
Warning
Fluid
1. Verify the color and terminal number when wiring.
Incorrect wiring can cause a switch to be damaged and may
result in a malfunction. Verify the color of wiring and the
terminal number in the instruction manual when wiring.
2. Avoid repeatedly bending or stretching the lead
wire.
Repeatedly applying bending stress or stretching force to the
lead wire will cause it to break.
3. Confirm proper insulation of wiring.
Make sure that there is no wiring insulation (contact with other
circuits, ground fault, improper insulation between terminals,
etc.). Overcurrent is flown and may result in a damage.
1. Never use in an environment, where explosive
gases are used.
The switches do not have an explosion-proof rating. Never use
in an environment, where explosive gases are used, as this
may cause a serious explosion.
2. Mount a switch in such locations, where no
vibration or shock (less than 98 m/s2) is affected.
[For air]
3. Use the switch within the specified fluid and
ambient temperature range.
Fluid and ambient temperatures are 0° to 50°C. Take
measures to prevent freezing fluid when below 5°C, since this
may cause damage to a switch and lead to a malfunction. The
installation of an air dryer is recommended for eliminating
condensate and moisture.
Never use a switch in an environment, where temperature
changes drastically even within the allowable ambient
temperature range.
1. Perform periodical inspections to ensure proper
operation of the switch.
Unexpected malfunctions and wrong operations may not
secure the safety.
2. Use caution when using a switch for an interlock
circuit.
When a pressure switch is used for an interlock circuit, devise
a multiple interlock system to prevent trouble or
malfunctioning. Verify the operation of the switch and interlock
function on a regular basis.
3. Do not disassemble or modify the main body.
Warning
Warning
Warning
1. Check regulators and the flow adjustment valves
before introducing the fluid.
If pressure or flow rate beyond the specified range are applied
to the switch, the sensor unit may be damaged.
[For air]
2. Fluids for measurement for this digital flow switch
are nitrogen and air.
Please note that accuracy cannot be guaranteed when other
fluids are used.
3. Never use flammable fluids.
4. Install a filter or mist separator on the upstream side
when there is a possibility of condensate and
foreign matter being mixed in with the fluid.
The rectifying device built into the switch will be clogged up
and accurate measurement will no longer be possible.
[For water]
5. Never use flammable fluids.
6. Install a filter in the inlet side when it is likely for
solid foreign objects to get mixed with fluids.
Flow Switches
Precautions 2
Be sure to read before handling.
16-11-3
ZSE
ISE
PSE
Z
ISE3
PS
Z
ISE 1
2
ZSP
ISA2
IS
ZSM
PF2
IF
Data
Series PF2A
Series PF2W
Series PF2A
Series PF2W
Remote Type
Integrated Type
Digital Flow Switch
Series PF2A/PF2W
1
2
3
4
5
6
For Air
For Water
Flow rate setting and monitoring are possible
with the digital display.
Two types for different applications
Integrated and remote type displays
Three types of output:
Switch, accumulated pulse, and analog outputs.
Switching from real-time flow rate to
accumulated flow is possible.
Two independent flow rate settings are possible.
Water resistant construction conforming to IP65
Flow rate measurement
range (l/min)
For Air For Water For High Temperature
Fluid (Water 90°C)
1 to 10
5 to 50
10 to 100
20 to 200
50 to 500
150 to 3000
300 to 6000
600 to 12000
0.5 to 4
2 to 16
5 to 40
10 to 100
0.5 to 4
2 to 16
5 to 40
Flow control of cooling water for
wafer temperature regulation and
high frequency electric power supply
Application examples
Flow control of N2 gas to prevent
detection camera shimmering and
lead frame oxidation
Flow control of pressurized
cooling water for welding gun
MULTI COUNTER:CEU5
ACOM COM COM
B
DC12V
GND F.G. R.S.
HOLD
BANK1 BANK2
COM
S.STOP
OUT1OUT2OUT3OUT4OUT5
AC100~240V
COUNT
PRESET
FUNC.
SD SGRD
RS-232C
UP
LEFT
RIGHT
DOWN
SEL. SET
MODE
The accumulated pulse output
function (100 l/pulse) enables remote
monitoring of accumulated flow.
Main line flow control
Flow control for each branch line
M/C
M/C
M/C
100 l/pulse
Pulse counter
Make possible the monitoring
of air flow from the main line
to each branch line.
For Air For Water
16-11-5
ZSE
ISE
PSE
Z
ISE3
PS
Z
ISE 1
2
ZSP
ISA2
IS
ZSM
PF2
IF
Data
P. 16-11-7
P. 16-11-17
P. 16-11-26
1 to 10
5 to 50
10 to 100
20 to 200
50 to 500
150 to 3000
300 to 6000
600 to 12000
16 l/min
4 l/min
100 l/min40 l/min
PF2A710
750
711
721
751
703H
706H
712H
PF2W704T
720T
740T
: Output from integrated display type and remote display unit type
: Output from remote sensor unit type
: Output from integrated display type and remote display unit type
: Output from remote sensor unit type
: Output from integrated display type and remote display unit type
: Output from remote sensor unit type
For Air
For Water
For High Temperature
Fluid (Water 90°C)
50 l/min
10 l/min
500 l/min
200 l/min
100 l/min
12000 l/min
6000 l/min
3000 l/min
–
PF2A510
550
511
521
551
–
PF2A
30
31
Integrated
display type
Remote type
Display unit Sensor unit
Output specifications Port size (Rc, NPT, G)
1/8 1/4 3/8 1/2 11/2
12
Switch output Analog output
Accumulated
pulse output
0.5 to 4
2 to 16
5 to 40
10 to 100
Flow rate
measurement
range l/min
PF2W
30
33
PF2W704
720
740
711
PF2W504
520
540
511
Integrated
display type
Remote type
Display unit Sensor unit
Port size (Rc, NPT, G)
3/8 1/2 13/4
Output specifications
Switch output Analog output
Accumulated
pulse output
Flow rate
measurement
range l/min
Port size (Rc, NPT, G)
3/8 1/2
Integrated
display type
Remote type
Display unit Sensor unit
Flow rate
measurement
range l/min 3/4
Output specifications
Switch output Analog output
Accumulated
pulse output
0.5 to 4
2 to 16
5 to 40
PF2W
30
PF2W504T
520T
540T
16-11-6
PF2A7 10 01 27
Output specifications
NPN open collector 2 outputs
PNP open collector 2 outputs
Applicable model
PF2A710, PF2A750
PF2A711, PF2A721, PF2A751
PF2A710, PF2A750
PF2A711, PF2A721/PF2A751
For details about certified products
conforming to international standards,
visit us at www.smcworld.com.
Model
How to Order
Digital Flow Switch
For Air
Series PF2A
Nil
N
Wiring specifications
3 m lead wire with connector
Without lead wire
10
50
11
21
51
Flow rate range
1 to 10 l/min
5 to 50 l/min
10 to 100 l/min
20 to 200 l/min
50 to 500 l/min
Symbol
01
02
03
04
Port size
1/8
1/4
3/8
1/2
10
50
100
200
500
Applicable model
Flow rate (l/min) Output specifications
Nil
M
Nil
N
F
Thread type Unit specifications
Rc
NPT
G
PF2A710, PF2A750
PF2A711, PF2A721
PF2A751
Integrated
display type
With unit switching function
Fixed SI unit Note)
Note) Fixed unit:
Real-time flow rate: l/min
Accumulated flow: l
Port
size
Specifications
Measured fluid
Flow rate measurement range
Set flow rate range
Flow rate measuring range
Minimum set unit
Accumulated pulse flow rate exchange value (Pulse width: 50 ms)
Operating fluid temperature
Linearity
Repeatability
Temperature characteristics
Current consumption (No load)
Weight Note 3)
Port size (Rc, NPT, G)
Detection type
Display
Operating pressure range
Proof pressure
Accumulated flow range
Indicator light
Response time
Hysteresis
Power supply voltage
Real-time flow rate
Accumulated flow
Resistance Output
specifications
Enclosure
Operating temperature range
Withstand voltage
Insulation resistance
Vibration resistance
Impact resistance
Noise resistance
0.5 to 10.5 l/min
0.5 to 10.5l /min
1 to 10 l/min
0.1 l/min
0.1 l/pulse
2.5 to 52.5 l/min
2.5 to 52.5 l/min
5 to 50 l/min
0.5 l/min
0.5 l/pulse
5 to 105 l/min
5 to 105 l/min
10 to 100 l/min
1 l/min
1 l/pulse
10 to 210 l/min
10 to 210 l/min
20 to 200 l/min
2 l/min
2 l/pulse
25 to 525 l/min
25 to 525 l/min
50 to 500 l/min
5 l/min
5 l/pulse
PF2A710 PF2A750 PF2A711 PF2A721 PF2A751
Air, Nitrogen
l/min, CFM x 10–2 l/min, CFM x 10–1
±1% F.S. or less ±2% F.S. or less
290 g
150 mA or less
250 g
1/8, 1/4
160 mA or less
3/8
170 mA or less
1/2
l, ft3 x 10–1
0 to 50°C
±5% F.S. or less
Heater type
3-digit, 7-segment LED
1.0 MPa
0 to 999999 l
–50 kPa to 0.75 MPa
±3% F.S. or less (15 to 35°C, based on 25°C), ±5% F.S. or less (0 to 50°C, based on 25°C)
–50 kPa to 0.5 MPa
NPN or PNP open collector (same as switch output)
Lights up when output is ON OUT1: Green; OUT2: Red
1sec. or less
Hysteresis mode: Variable (can be set from 0), Window comparator mode: 3-digit fixed Note 5)
12 to 24 VDC (Ripple ±10% or less)
IP65
Operating: 0 to 50°C, Stored: –25 to 85°C (No condensation or freezing)
1000 VAC for 1 min. between external terminal and case
50 MΩ (500 VDC) between external terminal and case
10 to 500 Hz at whichever is smaller: 1.5 mm amplitude or 98 m/s2 acceleration, in X, Y, Z directions for 2 hrs. each (De-energized)
490 m/s2 in X, Y, Z directions 3 times each
1000 Vp-p, Pulse width 1 µs, Rise time 1 ns
Display unit
Note 1, 2)
Note 4)
Switch output
Accumulated pulse output
NPN open collector
Maximum load current: 80 mA; Internal voltage drop: 1 V or less (With load current of 80 mA)
Maximum applied voltage: 30 V; Two outputs
NPN open collector Maximum load current: 80 mA
Internal voltage drop: 1.5 V or less (With load current of 80 mA); Two outputs
Symbol
27
67
Note 1) For digital flow switch with unit switching function. (Fixed SI unit [(l/min, or l, m3 or m3 x 103)] will be set for switch type without the unit switching
function.)
Note 2) Flow rate display can be switched between the basic condition of 0°C, 101.3 kPa and the standard condition (ANR) of 20°C, 101.3 kPa, and 65%
RH.
Note 3) Without lead wire.
Note 4) Switch output and accumulated pulse output can be selected during initial setting.
Note 5) Window comparator mode — Since hysteresis will reach 3 digits, keep P_1 and P_2 or n_1 and n_2 apart by 7 digits or more. (In case of output
OUT2, n_1, 2 to be n_3, 4 and P_1, 2 to be P_3, 4.)
Note 6) The flow switch is comformed to CE mark.
16-11-7
ZSE
ISE
PSE
Z
ISE3
PS
Z
ISE 1
2
ZSP
ISA2
IS
ZSM
PF2
IF
Data
PF2A721/521
PF2A711/511
PF2A751/551
Output (OUT1) Indicator: Green
Output (OUT2) Indicator: Red
DOWN
U P
OUT2OUT1
SET
Component Parts
Component Parts
Connectors
Connector
size
M12
Number
of
pins
Correns Corporation
OMRON Corporation
Yamatake Corporation
Hirose Electric Co., Ltd.
DDK Ltd.
VA-4D
XS2
PA5-4I
HR24
CM01-8DP4S
4
Connectors shown below are applicable
(female contact).
Contact each manufacturer for details.
Manufacturer Applicable
series
Flow Characteristics (Pressure loss)
Pressure loss (kPa)
Flow rate (l/min)
Pressure loss (kPa)
Flow rate (l/min)
PF2A710/510 PF2A750/550
01 10
0.2
0.4
0.6
0.8
1.0
52.5 7.5 0 5 10 15 20 25 30 4035 45 50
0.5
1.0
1.5
2.0
2.5
3.0
Pressure loss (kPa)
Flow rate (l/min)
0100
2
4
6
8
10
10 25 50 75
Pressure loss (kPa)
Flow rate (l/min)
0200
5
10
15
20
20 50 100 150
Pressure loss (kPa)
Flow rate (l/min)
050100 150200 250 300 400350 450 500
10
20
30
40
50
Sensor Unit Construction
PF2A710/750
PF2A510/550
PF2A711/721/751
PF2A511/521/551
Flow direction
Flow direction
Operating Unit Descriptions
RESET Buttons LED Display
UP Button ( Button)
SET Button ( Button)
DOWN Button ( Button)
Lights up when OUT1 is ON.
Blinks when an overcurrent error
occurs on OUT1.
Lights up when OUT2 is ON.
Blinks when an overcurrent error
occurs on OUT2.
Displays the real-time flow rate,
accumulated flow, and set value.
The mark blinks when the
accumulated flow is being
measured.
Use this button to increase a set
value.
Use this button to change a set
value or any of the modes.
Use this button to decrease a set
value.
Press the and buttons simultaneously
to activate the RESET function.
This clears the unit when an abnormality
occurs and resets the accumulated flow
display to “0”.
No.
q
w
e
r
t
Description
Attachment
Seal
Mesh
Body
Sensor
Material
ADC
NBR
Stainless steel
PBT
PBT
Material
ADC
NBR
PBT
Stainless steel
PBT
PBT
No.
q
w
e
r
t
y
Description
Attachment
Seal
Spacer
Mesh
Body
Sensor
16-11-10
Series PF2A
FLOW SWITCH
FOR AIR
OUT1 OUT2
SET
UP
DOWN
DOWN
U P
SET
OUT1
FOR AIR
OUT2
FLOW SWITCH
Dimensions: Integrated Display Type for Air
PF2A710/750
PF2A711/721/751
44
54
60
82
98
40
50
4-ø4.5
17
58
67
6
1.6
24
2-Port size
Internal circuit and
wiring example
PF2A7--27(-M)
OUT2
12
to
24 VDC
OUT1
Brown
Black
White
Blue
3
2
4
1
Load
Load
+
–
PF2A7--67(-M)
12
to
24 VDC
OUT1
OUT2
Brown
Black
White
Blue
1
4
2
3
Load
Load
+
–
4
42
2-ø3.4
Flow direction
Flow direction
(41.5)
4–ø4.5
50
88
34
54
44
116
40 2-Port size
64
30
23
1.6
73
(41.5)
43
21
Connector pin numbers
Pin no.
1
2
3
4
Pin description
DC (+)
OUT2
DC (–)
OUT1
Main circuitMain circuit
43
to are terminal numbers.
16-11-11
ZSE
ISE
PSE
Z
ISE3
PS
Z
ISE 1
2
ZSP
ISA2
IS
ZSM
PF2
IF
Data
Series PF2A
Digital Flow Switch
For Air
Display
High Temperature Fluid Type (For Water)
Functions: PF2A, PF2W Refer to the operation manual how to set and to operate.
Flow rate measurement selection
Real-time flow rate and accumulated flow rate can be selected.
Up to 999999 of flow rate value can be accumulated.
Unit switching
Display
Real-time flow rate
l/min
CFM x 10–2, CFM x 10–1
Accumulated flow
l
ft3 x 10–1
For Air
CFM = ft3/min
High Flow Rate Type (For Air)
Display
Real-time flow rate
l/min
CFM
Accumulated flow
l, m3, m3 x 103
ft
3
, ft
3 x
10
3
, ft
3 x
10
6
Real-time flow rate
l/min
GPM
Accumulated flow
l
gal (US)
GPM = gal (US)/min
Note) Fixed SI unit [l/min or l] will be set for the type
without the unit switching function.
Note 1) Applicable for all integrated display types other than series
PF2A7H and remote type sensor display units.
Note 2) Only for series PF2A7H.
Flow rate conversion
Basic state: 0°C, 101.3 kPa
Standard state: 20°C, 101.3 kPa, 65%RH (ANR)
Switchable between these states.
Flow rate measuring unit confirmation
This function allows to confirm the accumulated flow rate
when real-time flow rate is selected and to confirm the
real-time flow rate when accumulated flow rate is selected.
Error correction
LED display Contents Solution
Note 2)
Note 2)
Note 1)
Note 1)
Note 1)
Note 1)
Note 2)
A current of more than
80mA is flowing to OUT1
A current of more than
80mA is flowing to OUT2.
The setting data has
changed for whatever
reasons.
The flow rate is over the
flow rate measurement
range (for air only).
Check the load and wiring
for OUT1.
Check the load and wiring
for OUT2.
Perform the RESET
operation, and reset all
data again.
Reduce the flow rate until it
is within the flow rate
measurement range, using
an adjustment valve.
Key lock
This function prevents incorrect operations such as
changing the set value accidentally.
Accumulation clearance
This is to clear the accumulated value.
Initialization of setting (Only for series PF2A7H)
This is to restore the setting to the initial state when
dispatched from the factory.
Real-time switch output ( )
Output types
Real-time switch output, accumulated switch output, or
accumulated pulse output can be selected as an output type.
YES
NO
YES
NO
“P”
OUT1 Output
mode
• Window comparator mode
H: Hysteresis
• Window comparator mode
H: Hysteresis
• Hysteresis mode
• Hysteresis mode
ON
OFF
P-1P-2
ON
OFF
n-1n-2
ON
OFF P-1 P-2
HH
HH
ON
OFF n-2n-1
High flow rate →
High flow rate →
High flow rate →
High flow rate →
∗
OUT2 is the same.
“n”
Accumulated switch output ( )
“P”
OUT1 Output
mode
ON
OFF P-3
High flow rate →
“n”
ON
OFF n-3
High flow rate →
Note 1)
Accumulated pulse output ( )
50 msec
ON
OFF
ON
OFF
“P”
OUT1 Output
mode
“n”
Note 1)
Note 1) Output mode is set
to inverted output at
the factory before
shipment.
Note 1) Output mode is set to inverted output at the
factory before shipment.
Note 1) For digital flow switch with unit switching function.
(Fixed SI unit [l/min, or l, m3 or m3 x 103] will be set
for switch types without unit switching function.)
Refer to the specifications of display unit for the flow
rate value per pulse.
16-11-31
ZSE
ISE
PSE
Z
ISE3
PS
Z
ISE 1
2
ZSP
ISA2
IS
ZSM
PF2
IF
Data
Digital Flow Switch Series PF2A/PF2W
Series
PF2A/PF2W
Specific Product Precautions 1
Be sure to read before handling.
Design and Selection
Warning
Mounting
Thread
Rc 1/8
Rc 1/4
Rc 3/8
Rc 1/2
Tightening torque N⋅m
7 to 9
12 to 14
22 to 24
28 to 30
1. Mount switches using the proper tightening
torque.
When a switch is tightened beyond the specified tightening
torque, the switch may be damaged. On the other hand,
tightening below the specified tightening torque may cause
the installation screws to come loose during operation.
2. Apply wrench only to the metal part of the
pipings when installing the flow switch onto
the system piping.
Do not apply wrench to anything other than the piping
attachment as this may damage the switch.
3. Monitor the flow direction of the fluid.
Install and connect piping so that fluid flows in the direction
of the arrow indicated on the body.
4. Remove dirt and dust from inside the piping
using an air blower before connecting piping
to the switch.
5. Do not drop or bump.
Do not drop, bump, or apply excessive impacts (490 m/s2)
while handling. Although the external body of the switch
(switch case) may not be damaged, the inside of the switch
could be damaged and cause a malfunction.
6. Hold the body of the switch when handling.
The tensile strength of the cord is 49N. Applying a greater
pulling force on it can cause a malfunction. When handling,
hold the body of the switch – do not dangle it from the cord.
7. Do not use until you can verify that
equipment can operate properly.
Following mounting, repair, or retrofit, verify correct
mounting by conducting suitable function and leakage tests
after piping and power connections have been made.
8. Avoid the mounting orientation with the
bottom of the body facing up.
The switch can be mounted in any way such as vertically or
horizontally, however, avoid the mounting orientation with the
bracket on the bottom of the body facing upward.
1. Operate the switch only within the specified
voltage.
Use of the switch outside the range of the specified voltage
can cause not only malfunction and damage of the switch but
also electrocution and fire.
2. Do not exceed the maximum allowable load
specification.
A load exceeding the maximum load specification can cause
damage to the switch.
3. Do not use a load that generates surge
voltage.
Although surge protection is installed in the circuit at the
output side of the switch, damage may still occur if a surge is
applied repeatedly. When a surge generating a load such as a
relay or solenoid is directly driven, use a type of switch with a
built-in surge absorbing element.
4. Since the type of fluid varies depending on the
product, be sure to verify the specifications.
The switches do not have an explosion proof rating. To prevent
a possible fire hazard, do not use with flammable gases or
fluids.
5. Monitor the internal voltage drop of the switch.
When operating below a specified voltage, it is possible that
the load may be ineffective even though the pressure switch
function is normal. Therefore, the formula below should be
satisfied after confirming the minimum operating voltage of the
load.
[For air]
6. Use the switch within the specified flow rate
measurement and operating pressure.
Operating beyond the specified flow rate and operating
pressure can damage the switch.
[For water]
7. Use the switch within the specified flow rate
measurement and operating pressure.
Operating beyond the specified flow rate and operating
pressure can damage the switch. Avoid especially the
application of pressure above specifications through a water
hammer.
<Examples of pressure reduction measures>
a) Use a device such as a water hammer relief valve to slow
the valve’s closing speed.
b) Absorb impact pressure by using an accumulator or elastic
piping material such as a rubber hose.
c) Keep the piping length as short as possible.
8. Design the system so that the fluid always fills
the detection passage.
Especially for vertical mounting, introduce the fluid from the
bottom to the top.
9. Operate at a flow rate within the flow rate
measurement range.
If operated outside of the flow rate measurement range, the
Karman vortex will not be generated and normal
measurement will not be possible.
Warning
Caution
Design and Selection
1. Data of the flow switch will be stored even
after the power is turned off.
Input data will be stored in EEPROM so that the data will not
be lost after the flow switch is turned off. (Data can be
rewritten for up to one million times, and data will be stored
for up to 20 years.)
[Series PF2A7H]
10. Sudden increase of flow rate may destroy the
flow sensor. Ensure to open/close the flow
control valve not to exceed the maximum flow
rate measurement values.
Thread
Rc 3/4
Rc 1
Rc 1 1/2
Rc 2
Tightening torque N⋅m
28 to 30
36 to 38
48 to 50
48 to 50
Supply
voltage – >
Internal voltage
drop of switch
Minimum operating
voltage of load
16-11-32
Series PF2A/PF2W
Specific Product Precautions 2
Be sure to read before handling.
1. Verify the color and terminal number when
wiring.
Incorrect wiring can cause the switch to be damaged and
malfunction. Verify the color and the terminal number in the
instruction manual when wiring.
2. Avoid repeatedly bending or stretching the
lead wire.
Repeatedly applying bending stress or stretching force to
the lead wire will cause it to break.
3. Confirm proper insulation of wiring.
Make sure that there is no faulty wiring insulation (contact
with other circuits, ground fault, improper insulation between
terminals, etc.). Damage may occur due to excess current
flow into a switch.
4. Do not wire in conjunction with power lines
or high voltage lines.
Wire separately from power lines and high voltage lines,
avoiding wiring in the same conduit with these lines. Control
circuits including switches may malfunction due to noise
from these other lines.
5. Do not allow loads to short circuit.
Although switches indicate excess current error if loads are
short circuited, all incorrect wiring connections cannot be
protected. Take precautions to avoid incorrect wiring.
1. Never use in the presence of explosive gases.
The switches do not have an explosion proof rating. Never use
in the presence of an explosive gas as this may cause a
serious explosion.
2. Mount switches in locations where there is no
vibration greater than 98 m/s2, or impact
greater than 490 m/s2.
3. Do not use in an area where surges are
generated.
When there are units that generate a large amount of surge in
the area around pressure switches, (e.g., solenoid type lifters,
high frequency induction furnaces, motors, etc.) this may
cause deterioration or damage to the switches' internal
circuitry. Avoid sources of surge generation and crossed lines.
4. Switches are not equipped with surge
protection against lightning.
Flow switches are CE compliant; however, they are not
equipped with surge protection against lightning. Lightning
surge protection measures should be applied directly to
system components as necessary.
5. Avoid using switches in an environment where
the likelihood of splashing or spraying of
liquids exists.
Switches are dustproof and splashproof; however, avoid using
in an environment where the likelihood of heavy splashing or
spraying of liquids exists. Since the display unit of the remote
type switches featured here is not dust or splash proof, the
use in an environment where liquid splashing or spraying
exists must be avoided.
[For air]
6. Use the switch within the specified fluid and
ambient temperature range.
Fluid and ambient temperatures are 0° to 50°C. Take
measures to prevent freezing fluid when below 5°C, since this
may cause damage to the switch and lead to a malfunction.
The installation of an air dryer is recommended for eliminating
condensate and moisture. Never use the switch in an
environment where there are drastic temperature changes
even when these temperatures are operated within the
specified temperature range.
[For water]
7. Use the switch within the specified fluid and
ambient temperature range.
The fluid and ambient temperatures range for the switches is
0° to 50°C (and 0° to 90°C for high temperature fluid). Take
measures to prevent freezing fluid when below 5°C, since this
may cause damage to the switch and lead to a malfunction.
Never use the switch in an environment where there are
drastic temperature changes even when these temperatures
fall within the specified temperature range.
Operating Environment
Wiring
1. When using a switch for high temperature
fluid, the switch itself also becomes hot due to
the high temperature fluid. Avoid touching the
switch directly as this may cause a burn.
Warning
Warning
Usage
Warning
[For air]
9. Never mount a switch in a place that will be
used as a scaffold during piping.
Damage may occur if an excessive load is applied to the
switch.
10. Be sure to allow straight pipe length that is
minimum 8 times the port size upstream and
downstream of the switch piping.
When abruptly reducing the size of piping or when there is a
restriction such as a valve on the upstream side, the
pressure distribution in the piping changes and makes
accurate measurement impossible. Therefore, flow
restriction measures such as these should be implemented
on the downstream side of the switch.
[For water]
11. Never mount a switch in a place that will be
used as a scaffold during piping.
Damage may occur if an excessive load is applied to the
switch. Especially when the switch supports the piping, do
not apply a load of 15 N·m or more to the metal part of the
switch.
12. Be sure to allow straight pipe length that is
minimum 8 times the port size upstream and
downstream of the switch piping.
When abruptly reducing the size of piping or when there is a
restriction such as a valve on the upstream side, the
pressure distribution in the piping changes and makes
accurate measurement impossible. Therefore, flow
restriction measures such as these should be implemented
on the downstream side of the switch.
When used with the downstream side open, be careful of
the cavitation that is prone to occur.
Warning
Mounting
16-11-33
ZSE
ISE
PSE
Z
ISE3
PS
Z
ISE 1
2
ZSP
ISA2
IS
ZSM
PF2
IF
Data
Series PF2A/PF2W
Specific Product Precautions 3
Be sure to read before handling.
1. Check regulators and flow adjustment valves
before introducing the fluid.
If pressure or flow rate beyond the specified range are applied
to the switch, the sensor unit may be damaged.
[For air]
2. The fluids that the switch can measure
accurately are nitrogen and dry air. However,
only dry air can be measured with the high
flow rate type.
Please note that accuracy cannot be guaranteed when other
fluids are used.
3. Never use flammable fluids.
The flow velocity sensor heats up to approximately 150°C.
4. Install a filter or mist separator on the
upstream side when there is a possibility of
condensate and foreign matter being mixed in
with the fluid.
The rectifying device built into the switch will be clogged up
and accurate measurement will no longer be possible.
[For water]
5. The fluid that the switch can measure
accurately is water.
Please note that accuracy cannot be guaranteed when other
fluids are used.
6. Never use flammable fluids.
7. Install a filter on the inlet side when there is a
possibility of condensate and foreign matter
being mixed in with the fluid.
If foreign matter adheres to the switch’s vortex generator or
vortex detector, accurate measurement will no longer be
possible.
1. Since switch output remains OFF while a
message is displayed after the power is turned
on, start measurement after a value is
displayed.
2. Perform settings after stopping control
systems.
When the switch’s initial setting and flow rate setting are
performed, output maintains the condition prior to the settings.
With the 100, 200, and 500 l/min type switches for air, output
turns OFF when the switch’s initial setting and flow rate setting
are preformed.
3. Do not apply excessive rotational force to the
display unit.
The integrated type display unit can rotate 360°. Rotation is
controlled by the stopper; however, the stopper may be
damaged if the display unit is turned with excessive force.
[For air]
4. Be certain to turn on the power when the flow
rate is at zero.
Allow an interval of 10 minutes after turning on the power, as
there are some changes in the display.
5. Flow rate unit
Switch measures at mass flow rates without being influenced
by temperature and pressure. The switches use l/min as the
flow rate indicator unit, in which the volumetric flow is
substituted for mass flow at 0°C and 101.3 kPa. The
volumetric flow rate at 20°C, 101.3 kPa, and 65% RH (ANR)
can be displayed with the high flow rate type switches for air.
Others
Measured Fluid
Warning
Warning
Detection principle of digital flow switch for air
A heated thermistor is installed in the passage, and fluid absorbs heat from
the thermistor as it is introduced to the passage. The thermistor's resistance
value increases as it loses heat. Since the resistance value increase ratio
has a uniform relationship to the fluid velocity, the fluid velocity can be
detected by measuring the resistance value. To further compensate the fluid
and ambient temperature, the temperature sensor is also built into the switch
to allow stable measurement within the operating temperature range.
Fluid velocity
detection element
Temperature
compensation element
Detection principle of digital flow switch for water
When an elongated object (vortex generator) is placed in the flow,
reciprocal vortexes are generated on the downstream side. These vortexes
are stable under certain conditions, and their frequency is proportional to
the flow velocity, resulting the following formula.
f = k x v
f: Frequency of vortex v: Flow velocity k: Proportional constant
(determined by the vortex generator's dimensions and shape).
Therefore, the flow rate can be measured by detecting this frequency.
Fluid
Vortex generator Vortex detector
This flow switch uses l/min
as the flow rate indicator
unit. The mass flow is
converted and displayed
under the conditions of 0°C
and 101.3 kPa.
The conversion conditions
can be switched to 20°C
and 101.3 kPa with high
flow type switches.
1. Perform periodical inspections to ensure
proper operation of the switch.
Unexpected malfunctions may cause possible danger.
2. Take precautions when using the switch for an
interlock circuit.
When a pressure switch is used for an interlock circuit, devise
a multiple interlock system to prevent trouble or
malfunctioning, verify the operation of the switch and interlock
function on a regular basis.
3. Do not disassemble or perform any conversion
work on flow switches.
Maintenance
Warning
Measured Fluid
Warning
∗ Top view
16-11-34
Sensor
1
l
/min 5 l/min
10 l/min
20 l/min
50 l/min 100 l/min 200 l/min 500 l/min
Flow rate range
PF2A510
PF2A550
PF2A511
PF2A521
PF2A551
Sensor Flow rate range
PF2W504
PF2W504T
PF2W520
PF2W520T
PF2W540
PF2W540T
PF2W511
Rated flow rate range of sensor
Set flow rate range of sensor
0.5 l/min 4 l/min
0.35 l/min
4.5 l/min
2 l/min
1.7 l/min
40 l/min
45 l/min
16 l/min
17l/min
5 l/min
3.5 l/min
10 l/min 100 l/min
110 l/min
7 l/min
1 l/min 10 l/min
0.5 l/min
10.5 l/min
5 l/min
2.5 l/min
100 l/min
105 l/min
50 l/min
52.5 l/min
10 l/min
5 l/min
20 l/min 200 l/min
210 l/min
10 l/min
50 l/min 500 l/min
525 l/min
25 l/min
0.5 l/min
2 l/min
5 l/min
10 l/min 20 l/min 40 l/min 100 l/min
<For Air: PF2A>
<For Water: PF2W>
Caution
Set Flow Rate Range and Rated Flow Rate Range
Set the flow rate within the rated flow rate range.
The regulating flow rate range is the range of flow rate that can be set on the controller.
The rated flow rate range is the range of flow rate that satisfies the specifications (accuracy, linearity, etc.) of the sensor.
Although it is possible to set a value outside the rated flow rate range, the specifications will not be guaranteed even if the value stays
within the regulating flow rate range.
Series PF2A/PF2W
Specific Product Precautions 4
Be sure to read before handling.
16-11-35
ZSE
ISE
PSE
Z
ISE3
PS
Z
ISE 1
2
ZSP
ISA2
IS
ZSM
PF2
IF
Data
