CN203232334U - Constant temperature protection device for electrochemical sensors - Google Patents

Abstract

The utility model relates to a constant temperature protection device for an electrochemical sensor, which comprises a casing, an air intake pipe and an exhaust pipe connected with the casing, and a resistance wire wound outside the casing. The casing is composed of a base and a top cover screwed together. The hollow body has a thermal insulation cover on the outer wall of the base, and a resistance wire is wound on the outer wall of the base. An air inlet and an air outlet are set in the base. The air inlet pipe is wound outside the resistance wire and then connected to the air inlet, and the exhaust pipe is connected to the air outlet. The outer ports of the intake pipe and the exhaust pipe protrude from the insulation cover. The utility model is suitable for the working application of electrochemical sensors in portable instruments or on-line monitoring equipment under various gas ambient temperatures. The constant temperature measurement system of the electrochemical sensor does not have high requirements for the working power supply. The current signal is processed by the circuit into a standard signal output of 4 ~ 20mA, which can be directly integrated into the gas detection equipment for data docking, eliminating the temperature impact to the greatest extent. The influence of the electrochemical sensor effectively improves the measurement accuracy.

Description

Constant temperature protection device for electrochemical sensors

technical field

The utility model relates to a heat preservation device, in particular to a constant temperature protection device for an electrochemical sensor.

Background technique

The earliest electrochemical sensors date back to the 1950s, when they were used for oxygen monitoring. By the mid-1980s, small electrochemical sensors were used to detect many different toxic gases in the PEL range and showed good sensitivity and selectivity. At present, various electrochemical sensors are widely used in many online monitoring systems and portable measuring instruments.

A typical electrochemical sensor consists of a sensing electrode and a counter electrode separated by a thin electrolytic layer. The gas first reacts with the sensor through tiny capillary-type openings, then a hydrophobic barrier, and finally reaches the electrode surface. Sensing electrodes can employ either an oxidation mechanism or a reduction mechanism. These reactions are catalyzed by electrode materials designed for the gas being measured. A current proportional to the gas concentration to be measured flows between the positive and negative electrodes through a resistor connected between the electrodes. Measuring this current determines the gas concentration. Electrochemical sensors are often referred to as amperometric gas sensors or micro fuel cells due to the electrical current generated during this process.

Electrochemical sensors are very sensitive to temperature. In general, the sensor readings are higher when the temperature is higher than 25°C and lower when the temperature is lower than 25°C. Temperature effects are typically 0.5% to 1.0% per degree Celsius, depending on manufacturer and sensor type. Temperature affects span and baseline zero outputs.

Currently, this type of electrochemical sensor is simply insulated by installing an insulation layer on the outside, but the effect is not ideal. the

Contents of the invention

The purpose of the utility model is to provide a low-cost constant temperature protection device for the electrochemical sensor, which can keep the electrochemical sensor warm and ensure its stable operation.

The purpose of this utility model is achieved in that the constant temperature protection device of the electrochemical sensor comprises a housing, an intake pipe and an exhaust pipe communicated with the housing, a resistance wire wound outside the housing, and the housing is composed of a base and a top cover. The hollow body composed of screw joints has an insulation cover on the base coat, a resistance wire is wound on the outer wall of the base, an air inlet and an air outlet are set in the base, the air inlet pipe is wound outside the resistance wire and then connected with the air inlet, and the exhaust pipe is connected with The air outlet is connected, and the outer port of the air intake pipe and the exhaust pipe stretches out of the insulation cover. the

Due to the implementation of the above technical proposal, the utility model is suitable for the working application of the electrochemical sensor in the portable instrument or on-line monitoring equipment under various gas ambient temperatures. The constant temperature measurement system of the electrochemical sensor does not have high requirements for the working power supply. The current signal is processed by the circuit into a standard signal output of 4 ~ 20mA, which can be directly integrated into the gas detection equipment for data docking, eliminating the temperature impact to the greatest extent. The influence of the electrochemical sensor effectively improves the measurement accuracy.

Description of drawings: the technical scheme of the utility model is provided by the following drawings and examples:

Figure 1 is a schematic structural diagram of a constant temperature protection device for an electrochemical sensor.

Legend: 1. Air intake pipe, 2. Insulation cover, 3. Electrochemical sensor, 4. Circuit board, 5. Top cover, 6. Circuit chamber, 7. Insulation chamber, 8. Base, 9. Resistance wire, 10. Row Trachea, 11, temperature probe.

Detailed ways:

The utility model is not limited by the following examples, and the specific implementation manner can be determined according to the technical scheme of the utility model and actual conditions.

Embodiment: As shown in FIG. 1 , the constant temperature protection device for an electrochemical sensor includes a housing, an air intake pipe 1 and an exhaust pipe 10 communicating with the housing, and a resistance wire 9 wound outside the housing. The housing is a hollow body composed of a base 8 and a top cover 5 screwed together. The inner cavity of the top cover 5 is a circuit cavity, and a circuit board 4 is installed in it. The sensor 3 has a thermal insulation cover 2 on the base 8. The thermal insulation cover 2 is filled with thermal insulation cotton. The outer wall of the base 8 is wound with a resistance wire 9. An air inlet and an air outlet are provided in the base 8. The air intake pipe 1 is wound outside the resistance wire 9 and then It communicates with the air inlet, and the exhaust pipe 10 communicates with the air outlet. Intake pipe 1 and exhaust pipe 10 outer ports stretch out insulation cover 2. A through hole is opened on the bottom surface of the base 8, and a temperature-sensing probe 11 is inserted in the hole. The temperature-sensing probe 11 adopts a PT1000 platinum resistor, and its temperature-sensing accuracy error is not more than 0.5%.

During use, the resistance wire 9 is energized to heat the heat-insulating cover 2, and then the air entering the intake pipe 1 is heated, so that the air entering the heat-retaining cavity 7 is hot air. The temperature in the heat preservation cavity 7 can be accurately known by the temperature sensing probe 11, so that the size of the air current changes the heat generated by the resistance wire 9, adjusts the air temperature in the intake pipe 1, and changes the temperature in the heat preservation cavity 7. the

The above technical features constitute the best embodiment of the utility model, which has strong adaptability and best implementation effect, and non-essential technical features can be increased or decreased according to actual needs to meet the needs of different situations.

Claims (4)

1. the constant temperature protective device of an electrochemical sensor; comprise housing; the draft tube that is communicated with housing, gas outlet are wrapped in the outer resistance wire of housing, it is characterized in that: the cavity body that housing is spun and formed by base and top cover; outside base, be with muff; base outer wall is wound with resistance wire, offers air intake opening and gas outlet in the base, and draft tube is wrapped in resistance wire and is communicated with air intake opening more outward; gas outlet is communicated with the gas outlet, and draft tube and gas outlet external port are stretched out muff.

2. the constant temperature protective device of electrochemical sensor as claimed in claim 1, it is characterized in that: the top cover internal cavity is the circuit chamber, installing circuit board in it, the base internal cavity is incubation cavity, installing electrochemical sensor in it.

3. the constant temperature protective device of electrochemical sensor as claimed in claim 1 is characterized in that: fill heat-preservation cotton in the muff.

4. the constant temperature protective device of electrochemical sensor as claimed in claim 1, it is characterized in that: offer a through hole at base end face, the hole interpolation has temperature-sensing probe.

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