High Precision And High Stability NTC Temperature Sensor Using
Double-Layer Encapsulation Process
NTC temperature sensors are usually composed of 2 or 3 metal
oxides, mixed in a fluid-like clay, and calcined into a dense
sintered ceramic in a high-temperature furnace. Oxygen-bonded
metals tend to donate free electrons. Ceramics are generally
excellent insulators. But only theoretically, this is the case for
thermistor-type ceramics when the temperature approaches absolute
zero. However, as the temperature increases to more common ranges,
thermal excitations eject more and more free electrons. As more
electrons carry current through the ceramic, the effective
resistance decreases. Resistance changes very sensitively with
temperature. A typical change is a decrease of (-)7[%] to 3[%] per
degree Celsius. This is the most sensitive of any sensor suitable
for use over a wide temperature range.
The main technical parameters:
1. The rated zero-power resistance value R25 refers to the
zero-power resistance value of the thermistor measured at 25°C.
2. B value; defined as the ratio of the difference of the natural
logarithm of the zero-power resistance value at two temperatures to
the difference between the two temperatures.
3. Thermal time constant; under zero power conditions, when the
temperature changes suddenly, the time required for the temperature
of the thermistor body to change by 63.2% of the temperature
difference between the beginning and the end.
4. Dissipation coefficient; at a specified ambient temperature, the
ratio of the change in power dissipation of the thermistor to its
corresponding temperature change.
Type | NTC(thermistor) Temperature Sensor |
Temperature range | -50℃ ~ +300℃；Customized |
Accurancy | 1%；5%；10% |
| 1K；2K；2.2k；2.7k；3K；5K；7K；8K；12K；15K；20K；25K；30K；40K；47K；50K；60K；70K；100K；200K；230K；250K；470K；500K；1000K；Customized |
B value | 3274；3435；3470；3928；3950；3977；4100；4200；4400；Customized |
Probe Material | Stainless steel SS304； aluminum；copper；plastic；epoxy；glass |
Installation | Flanged；Surface；Threaded；Plastic；Straight；Film；Customized |
Wire Material | Heat shrinkable tube；PVC tube；glass fiber tube； tube |
Connector | Molex；JST；DuPont；CWB；CJT；U type；Customized |
Waterproof | IP67；IP68 |
Application
● Air conditioners, refrigerators, freezers, water heaters, water
dispensers, heaters, dishwashers, disinfection cabinets, washing
machines, dryers and other home appliances.
● Automobile air conditioner, water temperature sensor, intake air
temperature sensor, engine
● Switching power supply, UPS uninterruptible power supply,
frequency converter, electric boiler, etc.
● Intelligent toilet, electric blanket, etc.
Working principle of temperature sensor
Using the NTC thermistor under a certain measurement power, the
resistance value drops rapidly as the temperature rises. Utilizing
this feature, the NTC thermistor can be used to determine the
corresponding temperature by measuring its resistance value, so as
to achieve the purpose of detecting and controlling the
temperature.
Conventional product electrical performance parameters
Part No. | R25℃ (KΩ) | B(K) 25/50℃ | Rated Power @25℃(mW) | Dissipation Factor(δ) (mW/℃) | Thermal time Constant (S) |
TS502□3274A | 5.0 | 3274 | 10-20 | 2-4 | 5-20 |
TS502□3435B | 5.0 | 3435 | 10-20 | 2-4 | 5-20 |
TS502□3470A | 5.0 | 3470 | 10-20 | 2-4 | 5-20 |
TS502□3950A | 5.0 | 3950 | 10-20 | 2-4 | 5-20 |
TS103□3274A | 10.0 | 3274 | 10-20 | 2-4 | 5-20 |
TS103□3435B | 10.0 | 3435 | 10-20 | 2-4 | 5-20 |
TS103□3470A | 10.0 | 3470 | 10-20 | 2-4 | 5-20 |
TS103□3950A | 10.0 | 3950 | 10-20 | 2-4 | 5-20 |
TS103□4100A | 10.0 | 4100 | 10-20 | 2-4 | 5-20 |
TS153□3950A | 15.0 | 3950 | 10-20 | 2-4 | 5-20 |
TS153□4100A | 15.0 | 4100 | 10-20 | 2-4 | 5-20 |
TS203□3950A | 20.0 | 3950 | 10-20 | 2-4 | 5-20 |
TS203□4100A | 20.0 | 4100 | 10-20 | 2-4 | 5-20 |
TS223□4200A | 22.0 | 4200 | 10-20 | 2-4 | 5-20 |
TS403□3928A | 40.0 | 3928 | 10-20 | 2-4 | 5-20 |
TS503□3950A | 50.0 | 3950 | 10-20 | 2-4 | 5-20 |
TS503□4100A | 50.0 | 4100 | 10-20 | 2-4 | 5-20 |
TS104□3950A | 100.0 | 3950 | 10-20 | 2-4 | 5-20 |
TS104□4100A | 100.0 | 4100 | 10-20 | 2-4 | 5-20 |
TS104□4400A | 100.0 | 4400 | 10-20 | 2-4 | 5-20 |
Application
NTC temperature sensor not only outputs temperature signal, but
also integrates humidity measurement, and the signal output is also
changed from the original single signal to a variety of output
forms, which can carry out long-distance communication, data can be
recorded according to needs, upper limit alarm and automatic
control, etc. function.
The intelligent integrated NTC temperature sensor used today adopts
single-chip microcomputer technology, which is equipped with
multiple analog-to-digital signal converters. Its measurement
accuracy is higher, and the resolution is as high as 0.03 degrees.
It can also integrate a calendar clock to realize multiple
measurement modes. The output is more standardized and
standardized, which can effectively suppress the interference of
the surrounding environment on the temperature signal output,
making the measurement value more accurate.
►Design considerations and procedure of temperature sensor:
1. Choose the shape acoording to customer's design or assemble
requirements, and confirm the thermistor.
2. Confirm the thermistor element and other materials according to
customers' requirement
3. Choose the suitable resistance,B value and tolerance
4. Choose suitable moisture-proof and insulation technology to meet
customer's requirement
5. Choose suitable encapsulation structure to meet performance
requirements of mechanical shock resistance
6. Meet customer's special requirements.
Features
Fast reponse time
Moisture proof, waterproof
Easily assemble
Customized available
Application
● Air conditioners, refrigerators, freezers, water heaters, water
dispensers, heaters, dishwashers, disinfection cabinets, washing
machines, dryers and other home appliances.
● Automobile air conditioner, water temperature sensor, intake air
temperature sensor, engine
● Switching power supply, UPS uninterruptible power supply,
frequency converter, electric boiler, etc.
● Intelligent toilet, electric blanket, etc.
Product Description
| Type | NTC Temperature Sensor |
| Resisitance | 1K~5M Ω(1k 5k 4.7k 10k 20k 30k 50k 100k 150k 200k 300k)Customized |
| Beta Value | 3380k 3435k 3500k 3950k 4050k 4150k 4250k 4450k Customized |
| Housing | Cooper/Stainless/aluminum/Brass/Plastic/Nylon/Others Customized |
| Wire | 20/22/24/26/28/30/32AWG PP/PVC/PTFE/PFA/TPE/FEP Customized |
| Connector | JST/SYP/MOLEX/DUPONT/TE Customized |
| Installation | Flanged/Surface/Threaded/Plastic/Straight/Film/LUG/SMD/THT
Customized |
| Accuracy | 0.1% 0.5% 1% 2% 3% 5% 10% Customized |
| Temperature range | -40~300 Customized |
| Wire Length | 10mm~10000mm Customized |
ApplicationsTemperature measurement and control of household air-conditioner,
refrigerator, icebox,water heater,drinking
machine,radiator,dishwasher, disinfector,washing machine, drying
machine,middle-or-low-temperature drying box and constant
temperature box.
Conventional product electrical performance parameters| Dongguan Linkun Electronic Technology Co., Ltd. |
| Main technical parameters of sensor series thermistor: |
| Model | Rated resistance value (R25) | B value | Operating temperature | Dissipation coefficient | Thermal time constant |
| Resistance value (KΩ) | Allowable deviation (±%) | Nominal value (K) | (mW/℃) | (S) |
| CWF-102-3435 | 1 | ±1% ±2% ±3% ±5% | 3435 | -40℃ ～ ＋120℃ | ≥3.0 in still air | ≤6.0 in still air |
| CWF-202-3435 | 2 | 3435 |
| CWF-2.252-3950 | 2.252 | 3950 |
| CWF-472-3950 | 4.7 | 3950 |
| CWF-502-3470 | 5 | 3470 |
| CWF-502-3950 | 5 | 3950 |
| CWF-682-3950 | 6.8 | 3950 |
| CWF-103-3435 | 10 | 3435 |
| CWF-103-3470 | 10 | 3470 |
| CWF-103-3600 | 10 | 3600 |
| CWF-103-3380 | 10 | 3380 |
| CWF-103-3977 | 10 | 3977 |
| CWF-103-4100 | 10 | 4100 |
| CWF-153-3950 | 15 | 3950 |
| CWF-203-3950 | 20 | 3950 |
| CWF-233-3950 | 23 | 3950 |
| CWF-303-3950 | 30 | 3950 |
| CWF-333-3977 | 33 | 3977 |
| CWF-403-3950 | 40 | 3950 |
| CWF-473-4013 | 47 | 4013 |
| CWF-503-3977 | 50 | 3977 |
| CWF-503-3990 | 50 | 3990 |
| CWF-503-4050 | 50 | 4050 |
| CWF-104-3950 | 100 | 3950 |
| CWF-104-3990 | 100 | 3990 |
| CWF-104-4200 | 100 | 4200 |
| CWF-204-3892 | 200 | 3892 |
| CWF-204-3917 | 200 | 3917 |
Working principle of temperature sensor
Using the NTC thermistor under a certain measurement power, the
resistance value drops rapidly as the temperature rises. Utilizing
this feature, the NTC thermistor can be used to determine the
corresponding temperature by measuring its resistance value, so as
to achieve the purpose of detecting and controlling the
temperature.
Reliability Test
| Test Item | Test Standard | Test method | Performance requirements |
| Zero Power Resistance | IEC 60539-1 | Immerse samples in the constant temperature bath at 25℃±0.005℃,test
steady resistance | Resistance tol ±1%
|
| B value | IEC60539-1 | Immerse samples in the constant temperature bath at 25℃,50℃(or
85℃), test steady resistance,and calculate B value | Resistance tol ±1%
|
| Free fall | IEC60068-2-32
| Fall height: 1.5±0.1m,Surface: Cement , 1 time | No obvious damage, R25 △R/R≤±1%
|
| Insulation | IEC60539-1
| 500V pressure on insulation shell test insulation resistance | >500MOhm
|
| Withstand voltage | IEC60539-1 | Withstand voltage: 1500V/AC ,Leakage current:2mA Lasting: 60sec
| No obvious damage
|
| Tension | IEC60068-2-21 | Pull uniform speed at the end, F>4.0KG(requested by customer)
| No obvious damage, R25 △R/R≤±1%
|
| Vibration | Q/HBm 108-94 | Test frequency: 10~500Hz,swing: 1.2mm acceleration: 30m/s2
Direction X,Y,Z Time:8Hour/direction | No obvious damage, R25 △R/R≤±1%
|
| Steady humidity and heat | IEC60068-2-78 | Temp:40±2℃ Humidity:92-95%RH Time:1000±24Hour | No obvious damage, R25 △R/R≤±1%
|
| Thermal time constant | EC60539-1 | Immerse in 25℃ water,after thermal balance,immerse in
85℃,resistance arrives 63.2%,calculate total time | <10 sec
|
| High temperature storage | IEC60068-2-2 | Temp:125℃±5℃ Time: 1000±24Hour | No obvious damage, R25 △R/R≤±1% |
| Cold and thermal shock | IEC60068-2-14 | -40℃~+125℃ T1:30min Cycle time:1000
| No obvious damage, R25 △R/R≤±1%
|
| Knock experiment | IEC60068-2-77 | Acceleration:250m/s2 Pulse lasting: 6ms Knock times: 1000 Recovery
time: 2 Hour
| No obvious damage, R25 △R/R≤±1%
|
| Low temperature storage | IEC60068-2-1 | Temp: 40±2℃ Time: 1000±24Hour
| No obvious damage, R25 △R/R≤±1%
|
| Salt spray | IEC60068-2-11 | Temp: 35±2℃ Collection hour : 1.0mL~2.0mL Time: determine per as
actual demand | No obvious damage, R25 △R/R≤±1%
|
