JPH09292273A - Water, temperature sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent a heater from abnormally heating by spacedly arranging a plurality of electrodes molded with a conductive rubber or resin in the lengthewise direction on the surface of a temperature sensor. SOLUTION: This temperature detecting element 1 is molded with a waterproof insulating body 2, a water detecting electroode 3A is arranged on the extreme end surface, and a water detecting electrode 3A' is arranged spacedly from it in the lengthwise direction on the surface, and the respective ones are molded with conductive rubber or conductive resins 4A, 4A'. The temperature detecting element 1 is connected to a temperature measuring device through lead wires 5A, 5A', the electrodes 3A, 3A' are respectively connected a water detector through lead wires 6A, 6A'. A thermistor is for the temperature detecting element 1, a silicone rubber or fluoloresin is for the waterproof insulating body 2, and a conductive silane rubber or conductive fluororesin is for the conductive rubber or the conductive resins 4A, 4A', respectively ideal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water and temperature sensor for detecting both the presence and the temperature of water at the same time.
The present invention relates to water and a temperature sensor suitable for use in an aquarium for aquarium fish, a cage, and the like.

[0002]

2. Description of the Related Art When it is necessary to maintain a constant water temperature, such as an aquarium for aquarium fish or a fish cage, a heater for immersing a temperature sensor in the water to measure the water temperature and heating the water based on the temperature is usually used. Is controlled to keep the water temperature constant.

In this case, if water evaporates and the water level drops, or if a force is applied to the cord of the temperature sensor for some reason, the sensor part goes out of the water,
The temperature sensor does not measure the temperature of the water, but rather measures the temperature of the air in the aquarium or the temperature of the room. As a result, even if the water temperature becomes abnormally high, energization of the heater is not stopped, and finally, an accident occurs in which a fish or the like in the water tank dies. In addition, even if the water tank is damaged or falls due to an earthquake, the temperature sensor is exposed to the air and measures the temperature of the air. Cause of.

In order to solve such a problem, it is only necessary to be able to detect the presence or absence of water at the same time as the detection of the temperature. Conventionally, a sensor is known in which a pipe electrode for liquid level detection and a cap electrode are arranged at intervals in the longitudinal direction, a thermistor for temperature detection is provided inside, and integrated with a resin. JP-A-60-21420).

[0005] This sensor is intended for use in a bath buzzer. If this sensor is used in an aquarium for ornamental fish or a fish cage, harmful metal ions are eluted from the electrodes, causing harm to the fish. Further, in a water tank or a pond using seawater, there is a problem that the electrode is corroded.

[0006]

SUMMARY OF THE INVENTION The present invention solves the problems of the conventional temperature sensor, and simultaneously detects the temperature,
It can also detect the presence or absence of water, eliminating problems caused by abnormal heating of the heater that occurs when the temperature sensor is exposed to the air, hardly causes corrosion, and does not elute harmful metal ions Another object is to provide a sensor that does not malfunction.

[0007]

As a result of intensive studies to solve the above-mentioned problems, the present inventor found that a plurality of electrodes molded with conductive rubber or resin are spaced in the longitudinal direction of the temperature sensor surface. The present invention has been completed based on the idea of having the function of detecting the presence or absence of water at the same time by arranging them separately.

That is, according to the present invention, a plurality of water detecting electrodes each molded with conductive rubber or conductive resin are provided at intervals in the longitudinal direction of the surface of the temperature sensor in which the temperature detecting element is molded with a waterproof insulator. Provided is a water / temperature sensor which is disposed separately and can detect the presence of water by conduction between the electrodes, and can detect both the presence and the temperature of water.

The waterproof insulator is preferably made of silicone rubber or fluororesin. Preferably, the conductive rubber is a conductive silicone rubber, and the conductive resin is a conductive fluororesin.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a water and temperature sensor according to the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an example of a water and temperature sensor according to the present invention, in which a temperature detecting element 1 is molded with a waterproof insulator 2 and a water detecting electrode 3 is provided on the tip surface thereof.
A is also provided with water detection electrodes 3A 'at intervals in the longitudinal direction of the surface, and each is molded with conductive rubber or conductive resin 4A, 4A'. The temperature sensing element 1 is connected to a temperature measuring device (not shown) with two lead wires 5A and 5A ', and the electrodes 3A and 3A' are connected to the lead wire 6
A and 6A 'are connected to water detectors (not shown), respectively.

As the temperature detecting element 1, a thermistor, a thermocouple or the like can be used, but the thermistor is particularly preferably used. As the waterproof insulator 2, a synthetic resin, a synthetic rubber, or the like can be used. In particular, silicone rubber and a fluororesin are excellent in waterproofness and insulating properties and have good water repellency. When water comes out of the water, water quickly flows down from the surface, and although the sensor is out, water remains on the surface of the waterproof insulator 2 and seems to be immersed in the water. This is preferable because no malfunction occurs.

As the water detecting electrodes 3A and 3A ', a normal electrode plate may be used. However, the lead wires 6A and 6A' are stripped of the insulating coating at the tips thereof to form bare wires. It may be 3A or 3A '.

The conductive rubber and the conductive resin 4 are not particularly limited, but it is preferable to use a conductive silicone rubber or a conductive fluororesin having excellent waterproofness and water repellency.

In the water and temperature sensor of the present invention, since the water detection electrodes 3A and 3A 'are arranged at intervals in the longitudinal direction of the surface of the sensor, it is possible to increase this interval, and the sensor is Despite being out of the water, there is almost no water remaining between the electrodes 3A and 3A ', causing a malfunction due to energization. In particular, when a water-repellent silicone rubber or fluororesin having good water repellency is used as the waterproof insulator 2, and a conductive silicone rubber having good water repellency or conductive fluororesin is used as the conductive rubber or conductive resin 4, , When the sensor goes out of the water, the water quickly flows down from the surface of the sensor, so that the possibility that the water remains between the electrodes 3A and 3A 'and the malfunction is further reduced.

Further, in the water and temperature sensor of the present invention, the water detection electrodes 3A, 3A 'are made of conductive rubber or conductive resin 4.
Since the electrodes 3A and 3A 'are not exposed on the surface, they are hardly corroded and elution of harmful metal ions is prevented.

The number of undetected electrodes 3A, 3A 'is
Usually, two pieces are sufficient, but three or more pieces may be provided if necessary.

[0017]

According to the water and temperature sensor of the present invention, when the water temperature is kept constant in an aquarium for aquarium fish, a fish cage, or the like, the sensor goes out of the water for some reason, or When the water runs out, abnormal heating of the heater that is heating the water can be reliably prevented, corrosion does not easily occur, harmful metal ions do not elute, and malfunctions hardly occur.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Temperature detection element 2 Waterproof insulator 3A, 3A 'Water detection electrode 4A, 4A' Conductive rubber or conductive resin 5A, 5A 'Temperature detection element lead wire 6A, 6A' Electrode lead wire

Claims (5)

[Claims] 1. A plurality of water detection electrodes molded with conductive rubber or conductive resin are arranged at intervals in the longitudinal direction of the surface of a temperature sensor in which a temperature detection element is molded with a waterproof insulator. A water and temperature sensor capable of detecting the presence or absence of water and the temperature thereof by making it possible to detect the presence of water by conduction between the electrodes. 2. The water and temperature sensor according to claim 1, wherein the waterproof insulator is silicone rubber. 3. The water / temperature sensor according to claim 1, wherein the waterproof insulator is a fluororesin. 4. The water and temperature sensor according to claim 1, 2 or 3, wherein the conductive rubber is a conductive silicone rubber. 5. The water / temperature sensor according to claim 1, wherein the conductive resin is a conductive fluororesin.