Application of NTC temperature sensor in medical equipment

July 30, 2021

Application of NTC temperature sensor in medical equipment

Application of NTC temperature sensor in medical equipment


From clinical thermometers to dialysis equipment, NTC's medical application is also crucial. NTC temperature sensors are generally used in digital thermometers, culture (constant temperature) boxes, skin sensors, urinary catheters, dialysis equipment and respirators to monitor temperature, blood flow or airflow.

Our most common electronic thermometer is composed of temperature sensor, liquid crystal display, button battery, application specific integrated circuit and other electronic components. It can quickly and accurately measure the human body temperature. Compared with the traditional mercury glass thermometer, it has the advantages of convenient reading, short measurement time and high measurement accuracy.

Electronic clinical thermometers use temperature sensors to output electrical signals, directly output digital signals or convert current signals (analog signals) into digital signals that can be recognized by internal integrated circuits, and then pass them through displays (such as liquid crystal, digital tube, LED matrix, etc.) Display the temperature in digital form, can record and read the highest value of the measured temperature.

The core component of an electronic thermometer is the NTC temperature sensor that senses temperature. The resolution of the sensor can reach ±0.01℃, the accuracy can reach ±0.02℃, the response speed is <2.8 seconds, and the annual resistance drift rate is ≤0.1% (equivalent to less than 0.025℃).

3. Application of NTC temperature sensor in electric vehicle battery

With the widespread application of new energy electric vehicles, battery capacity, safety, health and endurance have increasingly become the focus of attention.

Temperature to the temperature of an electric vehicle battery is one of the important factors affecting the remaining power and service life of the battery. At present, only the surface temperature of the battery is generally measured. The NTC temperature sensor is used to measure the surface temperature of the battery, which is attached to the surface of the car battery to measure the temperature. The general structure of the NTC temperature sensor used in the car is generally divided into several types:

1. The materials used for the metal fixed ring head:

(1) Copper nickel-plated material: 0.8mm metal thickness, with high melting point, high hardness, and bright surface;

(2) Copper tin plating material: 0.8mm metal thickness, but the melting point is not high enough, the hardness is not large, and the surface is not bright with copper and nickel plating;

(3) Stainless steel: 0.5-0.7mm thickness to prevent rust;

(4) Pure nickel terminal: 0.2-0.3mm thickness, high hardness, convenient welding, light and thin.

2. The head of the water droplet is encapsulated with epoxy resin

The temperature sensor encapsulated by epoxy resin is usually glued directly on the surface of the battery, so the temperature measurement effect may be worse than that of the metal fixing ring, and the stability is not high. Generally, this kind of head encapsulation is not used in high-end cars. Measure the battery temperature.