Sensor

*** Scroll down to the bottom of the page for the
purchase of this water level sensor and its metal rods.

Electrode water level sensor is also known as a “Conductivity Level Sensors”.

Electrode sensor basically requires physical contact with the water to detect the water level. The water act as resistance. Small electronic current will be passing through the water which helps the sensor to sense the water level. For this reason, not all liquid can use this sensor for detection. One example is oil, which has an insulating property in nature. If you need to measure the level of a non-conducting liquid, consider using an ultrasonic water level sensor.

For a typical water tank or rainwater level detection, the electrode sensor is an affordable and commonly used method to detect the amount of water in a tank compared to other water level sensing method.

Electrode Sensor for Water Level Detection

An electrode sensing needs at least two contact point to function. For electrode with only a single probe, the other end of the sensor wire will be connected to a metallic tank (usually of stainless steel material). The metallic tank will act as the second probe. If the tank is not metal, or you do not want to connect the sensor wire to your tank, you can use a two probe electrode.

For multiple water level detection, you will need more probes. You can place up to a maximum of 5x probe for 3-4 water level detection. If you need to differential more water levels, you may like to consider using an ultrasonic water level sensor which can provide a higher resolution of detecting the water level.

illustration from  website.

Reference:

• https://www.ia.omron.com/support/guide/33/introduction.html
• http://www.omron-ap.com/service_support/technical_guide/level_switch/further_information.asp

Electrode Holder (PS-5S)

    
illustration from  website.

Available models for a different number of probes.

• PS-5S (for 5 rods)
• PS-4S (for 4 rods)
• PS-3S (for 3 rods)

Mounting hole diameter to cut out for the electrode holder is Ø 65mm
(Replacement model full horn 3/4″ MB7052XL, 3/4″ NPS WR Housing)

Replaceable model from Panasonic

Depending on stock availability we may replaced stocks with Panasonic models. They are compatible parts.

• PS-5R
• PS-4R
• PS-3R

Check out below to order today.

Reference:

• OMRON product sheet
• Panasonic product sheet
• https://www.ia.omron.com/products/family/255/feature.html

Electrode Probe or Rod

illustration from  website.

Reference:

• http://www.omron-ap.com/service_support/FAQ/FAQ00743/index.asp
• https://www.ia.omron.com/products/family/257/lineup.html

Water Level Sensor Controller

The water level sensor works together with the controller 61F-GP-N to form a network of switch relay. These relay can be activated when the water level reaches a certain level.

The following is an illustration a connection wiring diagram from OMRON, how you can wire up a 4 rods electrode configuration to sense the water level at 3 critical water level.

Installation Information

Reference:

• https://www.ia.omron.com/support/guide/33/further_information.html

Electrode Sensor Rod Replacement

Electrode sensor rod can get worn off after a period of operation. The electrode can be replaced. You can send in photos of your electrode and its holder for a quotation on a replacement. Please provide us with the size/length of the electrode and also the type of liquid you are using the electrode for.

Please also note that when your electrode sensor is not working, there may also be a chance that the electronic sensing system is faulty. Do check if the sensing electronic system is in good working condition before proceeding to change the electrode.

Send us your enquiry today.

More Water Level Sensing Technologies

Click here to check out this page for more water level sensing technologies, or this page to compare other water sensing technologies.

This page introduces using water level detection solution in a water tank using ultrasonic sensor.

Ultrasonic sensor (similar to radar and sonar) is using acoustic means for detecting an object’s distance away from the sensor. Just like a bat, the sensor will generate an acoustic pulse. The radiated pulse will hit the targetted object and reflected back to the sensor. The time taken for the pulse to echo back to the sensor provides an estimation of a distance. Knowing that the speed of sound is constant (in an acoustic medium) the detected distance can be relatively consistent.

Features For Water Level Detection

Sensing Distance

Sensing distance for water tank application typically ranges from 1 to 5 meters. If further detection distance is required, the sensor will need more energy and a bigger acoustic surface to emit and receive the ultrasonic pulse. This means the ultrasonic sensor for water level detection is usually bigger in size.

The increase in sensing distance also affects the sensing speed (sensing frequency). For water level detection, detection speed usually is not an important issue.

• Sensing distance typically (1 to 5m)
• Dead-zone (0.2 to 0.6m)

An ultrasonic sensor is typically designed for a certain detection range for a specific application. This helps to eliminate the possible noise being reflected from the environment. This is especially noise within a confined space like a water tank. The trade-off for a robust ultrasonic sensor will result in a slower detection speed. Dead-zone is the near range region which the ultrasonic sensor cannot detect. It is a blind spot to the sensor.

Output Type

There are many types of output to choose from. A benefit of using ultrasonic sensor is its ability to measure the relatively distance or water level in a water tank. For this reason, most of the time we want an ultrasonic sensor that can provide us with an analogue output or is able to output digital data. An analogue output provides distance information for our water tank level application.

• Analogue output (0-10V, 4-20mA)
• Digital data. (example RS232, RS485)
• Electromechanical relay output (dry contact, normally opened, normally closed)
• NPN, Open Collector output

Relay (dry contact) or NPN output can only provide simple on/off information. It can only tell you if the water level is reached or not.

Power Supply Input

There are typically two types of power input (either DC or AC voltage) to the sensor. It is recommended to select an ultrasonic sensor using DC voltage supply for a water tank application. If water gets in contact with the DC power will only result in minor water/gas reaction.

High voltage 230Vac power touching the water can be a safety hazard. If using DC powered ultrasonic sensor is not a solution, you should earth the water or water tank as a protection. In case the power line touching the water, the electrical system will be tripped and shut down as a means of protection.

• 12Vdc or 24Vdc
• 230Vac

Product Housing

For normal water tank application, you can just use a normal ultrasonic sensor. If you are using the sensor under a stressful environment, you may like to consider getting a sensor that can withstand water or even chemical resistant.

• Waterproof (IP65, IP67)
• Chemical resistant
• Robust from microbial contamination

Teflon coating can protect the transducer from most types of chemical. For bio-sensitive labs or production line hygiene, you may even want to use stainless steel ultrasonic sensor (very smooth and polished surface) that can minimise the risk of microbial contamination.

Other Features

The installation location of an ultrasonic sensor can be sensitive. This is especially for installation within a water tank where multiple acoustic reflections can occur. It is best to install away from the wall. The narrow acoustic beam can also help to reduce the unwanted reflection.

• Easy to mount and deploy.
• Simple to configure.
• Programmable.
• Status and indicators.

Chemical Resistant Ultrasonic Water Level Sensor

QT50ULBQ

Click here for more information about QT50ULBQ.

Features:

• Sensing distance from 0.2 to 8m (resolution 1mm)
• Analog Output (0-10Vdc or 4-20 mA)
• Power Supply 13-30Vdc (40-100mA)
• Waterproof IP67, NEMA 6P rating
• Operating Temperature -20 to 70°C
• Housing Material PBT (Polybutylene terephthalate)

High-Resolution Ultrasonic Water Level Sensor

BUS M30M1-XC-60/600-S92K

Click here for more information about BUS M30M1-XC-60/600-S92K.

Features:

• Sensing distance from 0.6 to 8m (resolution <0.18mm)
• Analog Output (0-10Vdc or 4-20 mA)
• Power Supply 9-30Vdc (max 80mA)
• Waterproof IP67
• Operating Temperature -25 to 70°C
• Housing Material Nickel Plated Brass, PBTTPU, PU foamEpoxy resinGlass
• Fastening Nut M30x1.5

Ultrasonic Range Finder Water Level Detection

MaxBotix specialised in precision range-finder ultrasonic sensor which can be used for water level detection. Wide selection of ultrasonic products to choose from.

Other Ultrasonic Sensor References

• https://senix.com/toughsonic-ultrasonic-sensor-overview/
• https://proportionair.com/control-valve-accessories/ultrasonic-sensor/

Other Types of Water Tank Level Sensor

• Water level sensors
• Electrode water level sensors
• Water level detection using flow switch
• Rain water level sensor system
• Comparison table of various water level sensors

A float switch is a simple switching device which gets triggered when it is being lifted by the water/liquid. The float is designed to be less dense than the liquid, allowing it to float up when in contact with the liquid.

Float switch requires maintenance once in a while. For a liquid that is too dense, or sticky, it is not advisable to use a float switch. You may like to consider using an ultrasonic water level sensor instead. An

Common Application

• Automatic replenish water tank
• Fish tank water cycling
• Rain-water tank and drainage control system
• Water reservoir or Ponds
• Tracking water drainage system

Magnetic Float Switch

Products from      

Please click on the images to the respective product links.

A magnetic float switch is one of the most popular float switches in the market. It is simple and easy to install. The sensor has a minimum number of moving mechanical parts compare to other float switches, which means the probability of sensor failure is lesser.

The magnetic float switch uses a reed which is typically very small in size. The floating compartment is inserted with a small and strong NEO magnet. When the magnet is close to the reed switch, the switch will make a contact (activate short circuit).

The entire sensor can be small in size and light in weight because of the small component used.

• Small in size
• Small dry contact relay
• Come in plastic or stainless steel material

If the liquid in the water tank requires cleanliness or hygiene, there are stainless steel water level float switch available. For simple water tank application, a plastic version is good enough. If you do not want the sensor to be in contact with the sensor for potential contamination happening, you may like to consider using an ultrasonic water level sensor instead.

One disadvantage of this magnetic float switch is that you cannot use the switch itself to drive a high current load. The most current you can drive through this sensor is probably about 100 to 300mA. If you need to drive a high current device using this sensor switch, you will need to interface it with an additional relay.

Reference:

• http://www.cynergy3.com/blog/how-select-correct-float-switch

Mechanical Ball Float Switch

A mechanical ball float switch consists of a weighted ball and a micro switch built inside the housing. When the water level reaches the sensor, the sensor will start to float upwards. This upward position will roll the ball downwards with the help of gravity. When the ball rolled down, it will trigger and depressed the microswitch inside the sensor housing.

• Switch can conduct higher current
• Bigger in size
• Suitable to be used in a large tank or big ponds/rivers.

The sensor is usually bigger in size due to its trigger mechanism. The micro switch is bigger in size and is able to drive a higher current load (small motor) without using external relay interface.

Due to its dangling wire design, the sensor need not be secure at the required water level height. This is unlike the magnetic sensor as introduced earlier. This sensor can be pivoted to the side or bottom of the pond. When the water level reaches the height, the sensor will float up and the micro switch (dry contact) will be triggered.

Bilge Pump Float Switch

This is a bilge pump float switch which is a commonly used water sensor inside a boat yacht. Float water inside the boat hull will trigger this sensor. The sensor will run a bilge motor to pump the trapped water out of the boat/yacht into the open sea.

This bilge pump is specially designed for the marine industry. The material used in this sensor resist better under in a corrosive sea environment.

More Water Lever Sensors

There are many different types of water level sensors technologies available in the market.

For an overview of many other sensors technologies in a table, click to visit the water level sensors comparison page.

You can also check out the water level sensors for other technical details.

Rain sensor,

Float switch,

Ultrasonic sensor

This page presents a quick summary comparison between the various type of rain sensors available on the market.

For a detail of the various rain sensing technology, you can visit the rain sensor page.

Comparison between the Rain Sensors

The following is a summary of the various types of rain sensors that are discussed on this web page for a quick comparison.

Rain Sensor Types	Optical	Resistive	Capacitive	Mechanical	Sound	Weather Sensor
Features
Cheap	X	√	X	X	–	X
Reliability	√	X	√	√	√	√
Durable	√	X	√	√	√	√
Maintenance Free	√	X	√	X	X	X
Fast Detection	√	√	√	X	√	√
No Need Power Supply	X	X	X	√	X	X
Do not Collect Water	√	√	√	X	√	√
Simple to Install	√	X	√	√	X	X
Simple to Interface with Other Systems	√	X	√	√	–	X
Relay Contact Output (Dry Contact)	√	–	X	√	–	X
No Direct Contact with Water	√	X	√	X	X	X
Adjustable Sensitivity	√	√	X	X	X	√
Multiple Mode of Functions	√	X	√	X	X	√
Wide Range of Supply Voltage	9 to 24Vdc or Vac	X	12Vdc	Not Applicable	X	24Vdc

For Outdoor Rain Detection

For general purpose outdoor rain detection, consider the optical rain sensor. It is simple to maintain, and have relatively long lifespan compare to the other form of rain detection.

Available from PIC-CONTROL.

This optical rain sensor accepts 12-24Vdc and has a dry contact relay output which allows you to interface an automatic awning shade motorised system, or an alarm and alert system.

Check out this page for more information on this rain sensor.

To buy this rain sensor, click here.

For Protection of Sensitive Equipment

For expensive equipment sensitive to rain water, consider using a high-end weather sensor. This weather sensor is able to accurately predict the rain even before the rain starts falling. Built-in with infra-red, humidity, wind and temperature sensor. It is a must have sensor for protecting expensive outdoor equipment.

This rain sensor is superior compared to the rest of the sensors. The disadvantage of this sensor is the price. The integration to other system is not too difficult, but you may need an electronic engineer for the interfacing work if you are not formerly trained.

For Rain Water Detection without Power

Select a mechanical rain sensor if you prefer a simple 2 wire switch to be activated when the rain water is detected. The sensor requires no power input. It is a switch contact (dry contact) which will be activated when there is water in the sensor.

The sensor will need about half a day to a day to dry and deactivate itself. A simple and inexpensive rain sensor to have if you do not need a very fast rain sensing response.

Click here to purchase rainbird sensor.

For Budget Rain-Sensing

Other Better Resistive Rain Sensors

Click here for more resistive rain sensor available in the market.

More Rain Sensor Information

Check out more of the rain sensor products details from our rain sensor page.

This page provides a summary list of resistive rain sensor available on the market. You can buy these products online from Singapore.

If you are looking for more other types of rain sensors (using non-resistive technology), you can check out this other page.

You can also check out this page for a quick glance comparing rain sensors technologies available on the market.

Somfy Rain Sensor

Input power: 230Vac.

The output is dry contact relay.

Buy Somfy rain sensor

Kemo Rain Sensor

Power Input: 12Vdc (160mA)
Output: Relay: 25V, 2A
Dimension Size: 65 x 45 x 36mm (sensor surface 29 x 30mm)
Anti freeze heater on the sensor. Indicator for operation and rain detection.

Where to buy? Click here or here.

FAKRO Z-Wave Rain Sensor ZRD

Lockwood (ASSA ABLOY)

Power Input: 24-32 Vdc (300mA)
Operating Temperature: 0° to +60°C
Dimension Size: 60 x 50 x 16mm

Eltako Electronic Rain Detector Sensor

Rain, Temperature, Wind, Brightness sensor

Power Input: 24Vdc (6W)
Operating Temperature: -30° to +55°C (IP44)
Dimension Size: 118 x 96 x 77mm
Accessories available for wireless data transmitter FWS61

LW100 LEAF WETNESS / RAIN SENSOR

Power Input: 12Vdc (1mA)
Output: 0 – 5 Vdc
Dimension Size: 7.6 x 14mm
Accessories available for wireless data transmitter FWS61

HomeMatic Wireless Rain Sensor

Power Input: 7.5 – 30Vdc (250mA)
Operating Temperature: -20° to +55°C (IP44)
Dimension Size: 80 x 82 x 55mm
Weight: 266g
Build-in heater

Loxone Rain Sensor

Power Input: 24Vdc (50 – 180mA)
Output: 24V
Operating Temperature: -30° to +70°C (IP65)
Dimension Size: 70 x 62 x 37mm

Velux Rain Sensor

Rain Sensor from eibmarkt

DIY Rain Sensor

This is the cheapest rain sensor kit that you can purchase from the retail shops at Sim Lim Tower in Singapore for less than S$30. Simple and good education kit for learning electronics.

For those who like to build yourself a rain sensor, you can also check out the rain sensor open source design here.

Custom Rain Sensor Solution

PIC-CONTROL is providing custom rain sensor solution to our client.

Check out our rain sensor alert system or rain sensor awning automation shade system for further information.

Also, check out other rain sensor technologies and comparison between the rain sensors.

The following presents a comparison summary between the various type of water level detection methods. Each has its own advantages and disadvantages.

The subsequent sections talks about the commonly used sensors in the industries.

images reference from:

Lowest Cost Water Level Sensor

The magnetic float switch is a widely used as a water level detection sensor. It is simple and is mechanically driven. The float switch consists of a float, magnet and a reed switch which are fairly inexpensive.

The reed switch which will be activated when the magnet is near. The activated reed switch will form a dry contact which indicates that a water level is reached.

The disadvantage of a float switch is that it has to be in contact with the liquid in order to function. For this reason, high-density liquid will not be suitable (one example is thick oil). The float switch also comes with a stainless steel version instead of plastic.

The sensor is rather reliable due to its simple mechanism. It is also a recommended secondary sensor to install for safety purpose even if you are using other methods of water detection.

A magnetic float switch is a simple and reliable.

Check out this page for more information about the float switch as a water level sensing.

Water Level Sensor with Analog Output

The ultrasonic sensor (acoustic sensor) is suitable for applications that require the detection of the water level depth in a tank or the amount of water in the water tank. The water level detected has a higher resolution. This wide water level detection range is also known as a water level sensor with “analog output”.

Check out this page for more detailed information about selecting a ultrasonic sensor for water tank level detection application.

Water Level Sensor Suitable for your Application

There are many types of water level sensors technology available. Each has its own advantages and disadvantages.

Feel free to contact PIC-CONTROL if you are unsure which water level sensing technology is suitable for your application.

Reference:

• Various methods of measuring water level.