7178-590
For Sodium Hypochlorite Solution and Sodium Hydroxide Solution

Small-Size Electromagnetic Sensor VNS

Notes on piping1.

Handling Manual

Do not use the product where air can ingress. Also,
do not install it where an air pocket can easily occur(e.g., the upstream side of a falling pipe). Before
starting to use the product after installation, drain air
sufficiently.

2.

It is recommended to install the sensor as the fluid flows
from bottom to top in order to avoid influence of bubble,
dust, and/or dirt.

This indicates that if you ignore this instruction, danger
Danger3.

which may result in death or serious injury can occur.

adjustment value at the downstream of the product.
4.

This indicates that if you ignore this instruction, danger
Warning

5.

Provide 5D or longer straight pipe at the upstream of thesensor.

Cautiondamage (e.g., defect of the product) can occur.

6.

Provide a straight pipe at the downstream of the sensor
as long as possible.

7.

Notes on use

Do not install the product where a strong compression or
tension force or a strong load is applied to it.

8.

1. Do not use this product for a purpose which requires

Put and install the sensor in accordance with the flow
direction indicated on the product.

safety, such as atomic power generation, railways,
9.

aviation, vehicle, or playground equipment.

Do not drop, hit, or apply an excessive impact to the
product. Hold the body when you handle the product

2. Do not alter the product.

(never hold the cable).

3. Do not use this product for food, beverage, and/or

10. Provide a maintenance space where the product is

medical fluid because it does not conform to the sanitaryDangerDo not install the product on a piping system where an
impact pressure such as a water hammer can occur.

which may result in serious injury can occur.
This indicates that if you ignore this instruction, a physicalCautionInstall something that disturbs the flow such as flow

installed.

specifications.

11. If there are foreign substances, oil, etc in the pipe, wash

4. Do not use in an explosive atmosphere such as a

the pipe before installing the sensor.

combustible gas because it is not explosion-protected.
1.

5. If you measure a fluid not intended for a specific model,

Observe the specified torque for capnut shown below.

it may leak from the O-ring. Be sure you are using the

Do not apply an excessive torque. An excessive torquecorrect model for the correct fluid.

may break the sensor sleeve screw section and cause
leakage.
Warning

Use environment and target fluid

Caution

VNS20R: 4.2 N･m
If the fluid still leaks after tightening the torque with theabove torque value, do not tighten them with a higher
torque but check for dust adhered to the seal anddamage of the O-ring.
2.

Do not install the product in locations used as footholds.

Notes on cabling
1.

This products operates with 24V DC. Connecting it to a
AC power supply may cause a fire.

Danger2.

Observe the instructions given in this manual for cabling.

3.

Observe the rated range. Do not use a load exceeding
the permissible value.

1.

Keep the cables away from the power, motor cables, etc.

2.

Keep the product away from noise sources as far as
possible.

3.

It is recommended to electrically isolate power supply
and receiving instruments from other equipment.

Caution4.

Do not use a power supply of which voltage is unstable
or of which capacity is lower than the rated value.

5.

It is recommended to ground the FG terminal of thepower supply.

Notes on operation
1. This product cannot be used for billing application.
2. Do not use any display or output during 20 seconds after
Caution

VNS05R: 2.8 N･m
VNS10R: 2.8 N･m

1. The target fluids are sodium hypochlorite solution andsodium hydroxide solution. Observe the rated density(conductivity).
2. Never mix a fluid of which conductivity is extremely low(e.g., oil) even if the quantity is very small.
3. Never install the sensor unit where the fluid can freezeor its temperature can exceed 40C.
4. The product may malfunction if it is used in a fluid wherea stray current is flowing.
5. Observe the permissible pressure range (1 MPa or less)and flow rate range. Do not use the product under thecondition of the load exceeding the permissible value.
6. Since the product is not water-proof (IP64 orequivalent), do not install it where it can be submerged.
7. Keep the product away from a strong magnet or
magnetic field.
8. When mixing the solution with water, do it at thedownstream of the product9. When storing the product after passing the fluid throughit, be sure to wash it thoroughly.
10. When changing the setting of the product, stop thewhole of equipment before doing it.
11. Do not place the product where it is exposed to a direct
sunlight or heat radiated from a heat source.

6.

Do not apply an excessive tension to the cables.

7.

Be careful so that the cable tip is not soaked in water
during the cabling work.

power because it is the time the operation becomes stable.

1Wiring

Piping and installation

Refer to the figure below for electrical connection.

1. Piping
The installation position is not restricted as far as the sensor is

Keep the pull-up voltage at 28VDC or less for the output1 and 30VDC

always filled with the fluid. However, it is recommended to installor less for the output2, respectively, and the output sink current must

the sensor as illustrated below so that it may not be affected by

be 20 mA.

Power
supply電 源
Powersupply voltage (DC24VDC)
供給電圧(ＤＣ１２～２４V)

bubbles.

Flowsensor

ＧＮＤ
GND

流量センサー○: Recommended

Red (power
supply +)赤(電源＋)

: Attention must be paid to bubbles
×: Must be avoided

Receiver
受信器
Ｖ

White (output 1)
白(出力１)

Top

Top

Ｒ

Open
collector
オープン
input
コレクタ入力Yellow黄(出(output2)
力２)
ISBlue (Powersupply -)青(電源－)ＧＮＤ
GND

sink current) ＝
出力吸込電流)I S ((Output

V (Pull-up voltage)Ｖ(プルアップ電圧)
RＲ(プルアップ抵抗)(Pull-up resistance)≦20mA

Specifications

Bottom

Accuracy-guaranteed
flow rate range

Model

BottomVNS05R
VNS10R
VNS20R

Low-flow-cut flow rate

VNS○○RF
VNS○○RE
Constant flow mode: 0.05~1 [L/min]
Pulsating flow mode: 0.01~1 [L/min]Constant flow mode: 0.5~10 [L/min]
Pulsating flow mode: 0.1~10 [L/min]Constant flow mode: 3.0~60 [L/min]
Pulsating flow mode: 0.6~60 [L/min]
2.5% F.S. (in constant flow mode)

Accuracy

Top

BottomConstant-flow
characteristics

Unit pulse
Frequency pulse

Pulsating-flow
characteristics*

Top

Output pulse

Output pulse

Frequency pulse

2. Mounting

OutputAttach the O-ring to VNS, put the cap nut of the joint over thesleeve screw of VNS, and then tighten the nut at the specified
torque.
The standard torque is 2.8 N･m for VNS05R and VNS10R, and
4.2 N･m for VNS20R.
Apply adhesive to the connection point of the pipe and joint to fix

Environment
al durability

Cap nut

Material

Pipe

Humidity
Storage temperature

Main body
Electrode

WeightNon wetted part

Joint

Sodium hydroxide solution

1~12%
10~25%
14mS/cm or higher
0 to 40C (no freezing)
1 MPa or less
NPN open collector
20 mA
Output 1: 28 V DC, Output 2: 30 VDC
1V DC or less

Fluorine-contained rubber

Working temperature

Wetted part

VNS

Sodium hypochlorite solution

20%-1%
1.0%F.S.

O-ringPower supply voltage
Current consumption
Protection structure

O-ring100-20%5.0% RD

Earth ring

VNS05R
VNS10R
VNS20R
Switch output
Alert output

them.

100-20%20%-5%
2.0%RD
0.4%F.S.
2.5%RD
0.5%F.S.
Flow rate ratio against the upper limit of
the accuracy-guaranteed flow rate(%F.S. value)

20 to 400 [Hz]0.001 (standard) [L/P]
0.01 (standard) [L/P]
0.1 (standard) [L/P]
Level judgment, window judgment
Dry sensor, meter abnormality, excessive flow
noise, reverse flow, excessive flow
24V DC  10%
60 mA or less
IP64 (equivalent)-20 to +60C
35 to 85% (no dewing)-20 to +70C
PEEK
Hastelloy C22
Titanium(equivalent)

Frequency pulse

Unit
pulse

BottomFlow rate output

Fluid typeDensity
Conductivity
Fluid temperature
Pressure range
Output format
Maximum current
Inter-terminal
withstand voltage
ON time residual
voltage

Flow rate ratio against the upper limit of
the accuracy-guaranteed flow rate(%F.S. value)

VNS05R
VNS10R
VNS20R

Ethylene-propylene rubber

Top and bottom covers: PPS, Cable: Vinyl
chloride
Approx. 200 g
Approx. 200 g
Approx. 300 g* Flow rate characteristics for measuring pulsating flow from an electromagnetic
metering pump2LED indication- Alert items and display pattern
Alert item

A bicolor (green/red) LED indicates the flow rate or alert. An alert by

Voltage drop1

Turns off continuously for bothgreen and red.

Excitation failure or
memory error

2Turns on continuously.

Dry sensor

3

Excessive fluid noise

4

Reverse flow

5

Excessive flow

6

detection of abnormality is prioritized, and only an alert with thehighest priority is indicated.
Green: Indicates the flow rate with four blinking and lighting
patterns in three levels.
Red: Indicates an alert (fault detection) with six blinking andlighting on/off patterns in four levels.
1. Flow rate (green)- Display pattern for the Flow Rate Range
Flow rate range

Display pattern

Less than low-flow-cut flow rate
Low-flow-cut flow rate to 1/3 of theupper limit of theaccuracy-guaranteed flow rate
1/3 to 2/3 of the upper limit of theaccuracy-guaranteed flow rate
Higher than 2/3 of the upper limit of
the accuracy-guaranteed flow rate

Display patternPriority

Turns on continuously.
Blinks at 2-second interval by turning on
and off for 1 second respectively.
Blinks every second turning on and off
for 0.5 seconds respectively.
Blinks every 0.4-second turning on andoff for 0.2 seconds respectively.

Turns on and off for 0.3 seconds
respectively for one cycle, thenturns off for 1.7 seconds andrepeat them.
Turns on and off for 0.3 seconds
respectively for three cycles, thenturns off for 1.7 seconds andrepeat them.
Turns on and off for 0.3 seconds
respectively for two cycles, thenturns off for 1.7 seconds andrepeat them.
Turns on and off for 0.3 seconds
respectively for four cycles, thenturns off for 1.7 seconds andrepeat them.

乾 水sensor
検知
Dry

On
点灯

(Low-flow-cut flow rate to 1/3 of the upper limit of theaccuracy-guaranteed flow rate)
On

2S
0.3S
過 大 流 体 ノflow
イ ズnoise
検知
Excessive

消灯
Off

2S

Off
消灯

On
点灯

Off

0.3S
Reverse
逆 流 検 知flow(1/3 to 2/3 of the upper limit of the accuracy-guaranteed flow rate)
On

点灯
On

Off

消灯
Off

2S
0.3S
Excessive
過 大 流 量 検flow
知(Higher than 2/3 of the upper limit of the accuracy-guaranteed flow rate)

点灯
On

On
Off

Off
消灯

2S

0.3S

・Display pattern for pulsating flow

External dimensions

Blinks every 0.4-sec when there is a pulsatory flow and turns on
continuously when there is no pulsating flow.

Sleeve screw(Blinks when pulsatory flow is detected.)
On
Off

Inner diameter of sensor

2. Alert (red)Excitation failure

Current does not flow through the excitation coilcorrectly.

Memory error

Error has been detected with memory data.

Voltage drop

Power supply voltage has dropped.

Dry sensor

Rectangle portionof flow path

- Alert items

Measurement fluid has gone out of the flowsensor
and the sensor is not filled with it.

Rectangle portion offlow path

Normal measurement is not possible since an
Excessive flow noise

abnormal current is flowing through the measurement
fluid or air ingress.

Excessive flow

Measurement fluid is flowing in the reverse direction.

Unit:[mm]VNS05R

VNS10R

VNS20R

125% or more of the maximum flow rate for the model

φD

φ5.2

φ10

φ20

has been detected.

DL

4.6

9

18

DH

2.4

4.4

8.7

Dimension

Reverse flow

Cable length: 500 mm, Termination: Peel cable coating and twist
core wire (12 mm)

3

L

95

95

110

W

47

47

48

H

51

53

64

SleeveFor joint

For joint

For joint

screw

(16A)

(16A)

(20A)

Warranty- Warranty period
One year after the dispatch date from Aichi Tokei Denki facility.
- Warranty scope

We are making every effort to produce our products with high quality,
however if a defect which is subject to our liability should occur
during the warranty period under normal use, we shall repair the
product or replace it with a normal product for free.
Please understand that we shall determine whether the free remedy
shall apply to your situation after our investigation of the product.
Also please understand that the free remedy shall not be applied toa defect:(1) Caused by use which does not follow the instructions given in
our catalog, product specifications, and/or handling manual,(2) Caused by disaster such as a fire, earthquake, storm, flood, orlightening, or a destructive act such as a crime,(3) Caused by corrosion due to use in a corrosive environment,(4) Caused by acts of animals such as a dog, cat, rat, or insect,(5) Caused by a factor other than our product,(6) Which could not be foreseen with the science and technology
levels at the time of shipment,(7) Caused by a repair or alteration other than done by or
specified by us, and/or(8) Caused by an inappropriate inspection and/or maintenance orreplacement of a consumable.
Please note that "warranty" in this context means warranty for our
product alone and we shall not reliable for any damage resulting
from a defect of our product, including but not limited to a damage toequipment other than our product, loss of profit, loss of opportunity,transportation fee, and construction fee.

Aichi Tokei Denki Co., Ltd.
1-2-70 Chitose, Atsuta-ku, Nagoya, Aichi Prefecture 456-8691 JAPANContact us : Overseas Business Division
TEL.

+81-(0)52-661-5150

FAX.

+81-(0)52-661-6418

Aichi Tokei Denki homepage: https://www.aichitokei.co.jp/
The product specification might be changed without prior notice.

Ver.02022114