NTC (negative temperature coefficient) thermistor is a heat-sensitive semiconductor resistor. Its resistance value decreases as the temperature increases. The temperature coefficient of resistance is in the range of -2%/k~-6%/k, which is about that of metal. 10 times the temperature coefficient of resistance. Changes in the resistance value of the NTC thermistor can be caused by changes in the external ambient temperature, or can be caused by self-heating due to the flow of current. His various uses are based on this property. NTC thermistors are constructed from polycrystalline ceramics with mixed oxides. The conductive mechanism of this material is quite complex.

　　Huaju Electronics is an early professional manufacturer of NTC thermistors in China. The NTC thermistors produced by the company are widely used in various handheld devices and miniaturized electronic equipment, and are also widely used in various temperature measurement and temperature compensation occasions. Relying on its technical advantages in the field of thermostats, Huaju Electronics produces temperature sensor products with stable performance and reasonable prices. The products are widely used in military, medical, human life, industrial automation, automobiles, security and fire protection, home appliances, communications, etc. Fields and occasions that require temperature measurement or overheating protection.

　　NTC temperature sensors are usually composed of 2 or 3 metal oxides, mixed in a popular clay, and sintered into a dense sintered ceramic in a high-temperature furnace. Oxygen-bonded metals tend to donate free electrons. Ceramics are generally excellent insulators. But this is only theoretically the case with thermistor-type ceramics when the temperature is close to absolute zero. However, as the temperature increases to more common ranges, thermal excitations throw out more and more free electrons. As many electrons carry current through the ceramic, the effective resistance decreases. Resistance changes extremely sensitively with temperature. Typical changes are (-)7[%] to 3[%] reduction per degree Celsius.This is the most sensitive of any sensor suitable for use over a wide temperature range. The rated room temperature resistance depends on the resistivity, size and geometry of the base material, and the contact area of ​​the electrodes. A thermistor that is thick and narrow has a relatively high resistance, while a thermistor that is thin and wide has a lower resistance. Actual sizes are also very flexible, they can be as small as .010 inches or very small in diameter. There is almost no limit to the maximum size, but half an inch or less usually applies.

　　Temperature sensor structure:

　　NTC thermistor, probe assembly (combination). A finished thermistor assembly (combination) composed of a thermistor shell, extension lead, and sometimes a connector.

　　structure

　　Generally composed of NTC thermistor, probe (metal shell or plastic shell, etc.), extension lead, and metal terminal or connector

　　.principle

　　Using NTC thermistor, under a certain measurement power, the resistance value decreases rapidly as the temperature rises. Utilizing this characteristic, the NTC thermistor can be used to determine the corresponding temperature by measuring its resistance value, thereby achieving the purpose of detecting and controlling temperature.

　　application

　　● On air conditioners, refrigerators, freezers, water heaters, water dispensers, heaters, dishwashers, disinfection cabinets, washing machines, dryers and other home appliances.

　　● Automotive air conditioners, water temperature sensors, intake air temperature sensors, engines

　　● Switching power supply, UPS uninterruptible power supply, frequency converter, electric boiler, etc.

　　● Smart toilets, electric blankets, etc.

　　Features:

　　● High sensitivity and fast response speed

　　● Resistance and B values ​​have high precision and good consistency and interchangeability

　　● Adopting double-layer encapsulation process, it has good insulation and sealing properties and resistance to mechanical collision and bending.

　　● The structure is simple and flexible, and can be customized according to different design requirements of customers.

　　3. Product mark description:

　　

 

　　①NTC temperature sensor

　　②Sensor head packaging form and size

　　1-Epoxy resin packaging

　　2-Aluminum shell, copper shell, stainless steel shell and other packaging

　　3-Plastic shell packaging

　　4-Add fixed metal sheet

　　5-Special form packaging

　　③Nominal resistance value R25

　　Example: 103=10×103 =10000Ω=10KΩ

　　④Nominal resistance value accuracy code

　　F: ±1% G: ±2% H: ±3% J: ±5%

　　⑤B value 3950 means B value is 3950K

　　⑥B value accuracy code

　　F: ±1% G: ±2%

　　⑦B value range definition

　　A=B25/50 B=B25/85 X=Specify the two-point temperature B value

　　⑧Lead length

　　Lead length: 1000=1000mm 500=500mm

　　4. Outline structure and dimensions of various packaging forms (mm)

　　·CWF1 type (epoxy resin encapsulated)

Features: moisture-proof, good insulation, high reliability, small time constant, sensitive response.
Application scope: household air conditioners, refrigerators, etc.

code name	A	B	C	D
D	3	5	6	7
L1	5	10	15	15
L2	According to customer requirements
L3	5.0±0.5

 ·CWF2 type (aluminum shell, copper shell, stainless steel shell, etc. packaging):

Features: High stability under thermal shock, moisture-proof, solid and reliable structure, large dissipation coefficient, the test current can be larger than that of the epoxy resin package type under the same size conditions.
Application scope: various types of refrigerators, air conditioners, water heaters, water dispensers, thermostats, etc.

code name	A	B	C	D	E	F	G
D	3	5	5	5	6	6	6
L1	20	20	25	30	20	25	30
L2	According to customer requirements
L3	5.0±0.5

·CWF3 type (plastic shell package):
Features: good appearance and size consistency, strong temperature and moisture resistance, and high voltage resistance.
Application scope: various types of air conditioners, refrigerators, etc.

 

code name	A	B	C	D
D	2	3	4	5
L1	8	15	15	15
L2	According to customer requirements
L3	5.0±0.5

 

code name	A	B
D	8	8
L1	35	50
L2	According to customer requirements
L3	5.0±0.5

 

·CWF4 type (with fixed metal sheet):
Features: Flexible appearance and structure to meet the installation requirements of different occasions.
Application scope: fan control, industrial temperature instrument, etc.

E: Other types of
features: Flexible appearance and structure to meet the installation requirements of different occasions.
Application scope: fan control, industrial temperature instrument, etc.

·CWF5 type (special packaging form):
Features: small time constant, fast response, flexible and reliable use.

Application scope: water heater, electronic thermometer, etc.

C: Other types of
features: low time constant, fast response, flexible and reliable use.
Application scope: water heater, electronic thermometer, etc.

6. Main technical parameters

Product number	Nominal resistance	B value	dissipation coefficient	Thermal time constant	Operating temperature
	R25（KΩ）	A（25/50℃）K	(mW/℃)	(S)	(℃)
		B（25/85℃）K
CWF□-102□3270A	1	3270A	For type 1 package ≥2.0 For type 2 package ≥4.0	For type 1 package ≤15 For type 2 package ≤70	-55～+125℃ Can be customized if you have special requirements
CWF□-102□3950A	1	3950A
CWF□-202□3470A	2	3470A
CWF□-202□4000A	2	4000A
CWF□-202□3930A	2	3930A
CWF□-202□3483A	2	3483A
CWF□-2.252K□3935A	2.252	3935A
CWF□-2.55K□3740A	2.55	3740A
CWF□-302□3950A	3	3950A
CWF□-472□3470A	4.7	3470A
CWF□-472□3950A	4.7	3950A
CWF□-502□3950A	5	3270A
CWF□-502□3380A	5	3380A
CWF□-502□3470A	5	3470A
CWF□-502□3600A	5	3600A
CWF□-502□3950A	5	3950A
CWF□-682□3977A	6.8	3977A
CWF□-682□4200A	6.8	4200A
CWF□-802□3780A	8	3780A
CWF□-103□3270A	10	3270A
CWF□-103□3435B	10	3435B
CWF□-103□3470A	10	3470A
CWF□-103□3600A	10	3600A
CWF□-103□3950A	10	3950A
CWF□-103□3977B	10	3977B
CWF□-103□4100A	10	4100A
CWF□-153□3680A	15	3680A
CWF□-153□3950A	15	3950A
CWF□-153□4100A	15	4100A
CWF□-153□4150A	15	4150A
CWF□-203□3950A	20	3950A
CWF□-203□4150B	20	4150B
CWF□-203□4200A	20	4200A
CWF□-233□3950A	twenty three	3950A
CWF□-233□4200A	twenty three	4200A
CWF□-303□3899A	30	3899A
CWF□-303□3950A	30	3950A
CWF□-303□4200A	30	4200A
CWF□-40.27K□3900A	40.27	3900A
CWF□-40.27K□3979B	40.27	3979B
CWF□-403□3950A	40	3950A
CWF□-473□3950A	47	3950A
CWF□-473□3990A	47	3990A
CWF□-473□4150A	47	4150A
CWF□-49.12K□3979B	49.12	3979B
CWF□-503□3950A	50	3950A
CWF□-503□3990A	50	3990A
CWF□-503□4050A	50	4050A
CWF□-503□4150A	50	4150A
CWF□-104□3950A	100	3950A
CWF□-104□3990A	100	3990A
CWF□-104□4000A	100	400A
CWF□-104□4050A	100	4050A
CWF□-104□4150A	100	4150A
CWF□-104□4200A	100	4200A
CWF□-104□4250A	100	4250A
CWF□-104□4450A	100	4450A
CWF□-154□4370B	150	4370B
CWF□-154□4500A	150	4500A
CWF□-204□4250A	200	4250A
CWF□-474□4450A	470	4450A
CWF□-105□4700A	1000	4700A
CWF□-105□4730A	1000	4730A

Note:
·Fill in the sensor package form code and size in the first box; fill in the nominal resistance value in the second box; fill in the nominal resistance value accuracy code in the third box. ·When the accuracy of the nominal resistance value is ±1%, the corresponding error of the B value is ±1%, and the errors of the other B values ​​​​are ±2%.
·In addition to the above specifications, our company can also supply products according to the special requirements of users.
·For temperature sensors with a temperature measurement range exceeding 100°C, special instructions are required. The company's temperature sensor can reach a maximum temperature of 250°C.