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Precautions During Use

General Precautions for Water Level Sensor

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Detection target

  • Note that water level sensor is not designed to detect the levels of liquids with low relative permittivity (εs), such as ice, alcohol, oil, and others.

Water type

  • When using in a liquid which contains highly conductive substances such as salt, acid, and alkali solutions, this water level sensor can be electrically short-circuited and may not be able return a signal due to the conductivity between the sensing electrode and the inner wall of the tank. Be fully aware of the detection target before use to ensure proper application.

In applications where high purity water

  • In applications where high purity water is used, depending on conditions such as water purity, flow rate, temperature, etc., the electrode rod, hexagonal nut of SU304, and O-ring silicone rubber when used for a long period may affect the water purity due to elution. Please confirm suitability.

Detection sensitivity

  • Sensors other than the "LLW series" may not be able to detect the capacitance of liquid in small tanks or those made of insulator (plastic). In that case, attach a conductive metal plate, etc. of about [50 x (T + 1)] mm square to the outer wall surface of the tank.(Tank thickness T (mm)) Then, use a lead wire on the metal plate and connect it to the power supply GND line of the sensor or the housing with large conductivity.

Extended periods of time

  • When using the sensor in tap water together with a water heater for extended periods, caustic lime and polluted sludge sediment contained in the water will gradually accumulate.
    When the concentrated impurities accumulate between the inner wall of the tank and sensing electrode, the sensor may not be able to return a signal. To avoid this, periodically clean the electrode and remove the accumulated sediment.

Connection

  • The sensing electrode works by connection to part of an operating circuit. Be sure not to apply a voltage higher than the rated supply voltage to the electrode.

The effect of magnetism

  • If the magnet is brought close to the sensor case, the sensor may malfunction or the detection sensitivity may be affected. When a magnetic field is applied to the sensor, make a thorough verification in advance before deciding whether or not to use it.

The effect of high frequency

  • This sensor uses a weak high frequency. If electromagnetic waves in the frequency band of about 100kHz to about 3MHz are received from surrounding machines, the characteristics of the sensor may be affected. Please use it after sufficient evaluation in advance under the conditions of use actually used in the market. If the sensor is affected by the electromagnetic waves of the surrounding machinery, connect the 0V (GND line) of the sensor directly to the housing of the sensor mounting tank or via a capacitor of about 2,200PF. At this time, use a capacitor with a withstand voltage value that has a sufficient margin for the specifications. In particular, metal tanks and highly conductive detection liquids are susceptible to electromagnetic waves, and the sensor may not operate normally. Electromagnetic waves enter the sensor internal circuit from the detection electrode via a metal tank or detection liquid, and affect the characteristics of the sensor. Please use it after sufficient evaluation.

Free design of electrode shape and separation type

  • If you want to change the shape or material of the detection electrode, design a new one, or separate it, consider using our touch sensor (model: HTS-30Z) for the sensor part.

Non-explosion proof structure

  • This sensor is not explosion-proof. It cannot be installed in dangerous places with flammable or explosive liquids or gases.

About usage environment

  • If the detection liquid contains solid matter, the sensor may be damaged if it repeatedly hits the detection electrode (SUS304) or the case of the sensor due to the flow of the liquid. To use the sensor for a long period of time, remove solids (precipitates / deposits) regularly, check for contaminants, and use a structure that does not allow solids to hit.
  • Do not use or store in places subject to oil, chemicals, dust, corrosive, flammable or explosive liquids, or where corrosive, flammable or explosive gas is generated. Also, do not use or store the product in a place where sudden temperature changes occur, in direct sunlight, or in a place subject to vibration or shock. Condensation or freezing may result in incorrect characteristics.
  • Before using the sensor, be sure to check the actual operation under actual usage conditions (for example the installation method of the sensor or your product, installation location, and surrounding environment ). Only use after sufficient pre-evaluation, assessment of operation, performance, or reliability in a state representative of use in your product. Be sure to perform pre-evaluation for the items in advance that are not listed in the specifications.

High reliability applications

  • It is usually expected that failures or malfunctions of medical equipment, automobiles, aerospace equipment, nuclear control equipment, etc. will cause significant damage to life, body, property, etc., directly or indirectly. Please do not use it for applications that require extremely high reliability. In addition, ensure the safety of the entire system and be sure to provide safety functions to prevent secondary disasters.

 

 

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