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Pt100-CSMD Platinum Thin Film Resistance Temperature Sensor: A Universal High-Precision Temperature Measurement Solution
Core Technical Principles and Process Advantages of Pt100-CSMD
The core of the Pt100-CSMD lies in the use of physical vapor deposition (PVD) or sputtering technology to precisely attach a thin layer of platinum with a purity exceeding 99.99% onto a high-purity alumina ceramic substrate, forming a micron-level resistance pattern. Through laser trimming technology, the resistance value at 0°C is accurately adjusted to 100.00Ω (with tolerances meeting Class A or Class B requirements), ensuring high consistency between batches.
Compared with traditional wire-wound Pt100 sensors, the thin-film structure significantly reduces thermal mass, shortening the thermal response time (t0.5) to 3–8 seconds in air, and even 1–3 seconds in liquids or flowing gases. This characteristic of quickly capturing temperature transients is particularly critical in early warning for battery thermal runaway or high-speed process control. Simultaneously, the tight bonding between the thin film and the substrate grants the sensor excellent vibration resistance (capable of withstanding over 50g) and mechanical shock resistance, making it suitable for mobile devices or industrial sites with strong vibrations.
The overall sensor adopts a 316L stainless steel sheath or ceramic encapsulation, with a protection rating of IP67 or higher, supporting direct contact measurement in various media, including liquids, steam, gases, and solid surfaces.
Key Performance Parameters and Reliability Assurance
Nexisense Pt100-CSMD offers two accuracy options, Class A and Class B:
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Class A: ±(0.15 + 0.002|t|)°C
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Class B: ±(0.30 + 0.005|t|)°C
Excellent long-term stability: After continuous operation at 200°C for 1000 hours, the resistance drift is typically less than 0.04%, with the annual drift rate controlled within 0.01–0.02%. The self-heating effect is low (<0.1°C under 0.3–0.5mA excitation current), suitable for precision and low-flow velocity measurements.
The working temperature range is -50°C to +400°C (standard type), and the high-temperature version can be extended to +600°C. Insulation resistance >100MΩ (500VDC), withstanding voltage of 1500VAC/1min, meeting industrial electrical safety specifications. Leads support soldering, reflow soldering, and wave soldering, compatible with SMT/THT processes for easy large-scale automated production.
Typical Application Fields and Actual Engineering Value
In the field of instrumentation, the Pt100-CSMD is commonly used in temperature transmitters, laboratory calibration equipment, and process control instruments. Its high repeatability and linearity allow the overall error of multi-point calibration systems to be stabilized within ±0.1°C.
In new energy scenarios, the sensor is widely used in lithium battery BMS, charging piles, photovoltaic inverters, and other critical node temperature monitoring. The fast response capability allows for timely signal output at the early stages of abnormal temperature rise, supporting early warning and protection strategies for thermal runaway and enhancing battery system safety.
Regarding household appliance integration, temperature control points such as inverter air conditioner compressors, water heater liners, and smart kitchen appliance cavities benefit from its small size and high stability, achieving finer temperature regulation and reducing energy consumption and malfunctions.
In the industrial and aerospace fields, the sensor's vibration-resistant and corrosion-resistant properties ensure long-term maintenance-free operation in high-reliability situations such as environmental test chambers, chemical reactors, and wind tunnel equipment.
Practical Guide for Selection, Installation, and Use
Selection focus should be on the accuracy grade (Class A for high precision, Class B for economy), probe diameter (thin tubes for fast response, thick tubes for pressure resistance), lead material (glass fiber/PTFE/silicone, selected according to temperature and environment), and installation method (thread, sleeve, welding).
A three-wire or four-wire connection is recommended to eliminate the influence of lead resistance: the three-wire system basically cancels out the error, and the four-wire system (Kelvin method) achieves the highest precision. Excitation current should be controlled at 0.3–1mA to avoid self-heating. Paired with high-precision ADCs (such as 24-bit ΔΣ modules) or dedicated chips (such as MAX31865), a resolution of 0.01°C can be easily achieved.
During installation, ensure good thermal contact and avoid violent impacts or over-temperature; periodically (every 1–2 years) use a standard constant temperature source to verify the 0°C and 100°C points.
Frequently Asked Questions (FAQ)
| Question | Detailed Answer |
|---|---|
| Q1: What are the main differences between the Pt100-CSMD thin-film sensor and traditional wire-wound Pt100 sensors? | A1: Thin-film technology shortens the thermal response time to 1/3–1/5 of the traditional wire-wound type, the volume is smaller (sensing head starts from φ1.6mm), the vibration and shock resistance is stronger (withstands 50g vibration), production consistency is higher, and the cost is more optimized, while retaining the standard linearity and long-term stability of Pt100. |
| Q2: How to choose between Class A and Class B accuracy in actual engineering? | A2: Class A tolerance ±(0.15+0.002|t|)°C is suitable for high-precision situations such as laboratory calibration and critical BMS monitoring; Class B ±(0.30+0.005|t|)°C is cost-effective and meets the needs of industrial processes and household appliance temperature control. At 100°C, the Class A error is ≤0.35°C, and Class B is ≤0.8°C. |
| Q3: How does the thermal response speed of thin-film Pt100 specifically perform, and what factors restrict it? | A3: Typical t0.5 is 3–8 seconds in air, and 1–3 seconds in water/oil flowing media. The thinner the probe diameter, the higher the media flow rate, and the better the thermal contact, the faster the response. In actual engineering, a φ3mm probe performs significantly better than a traditional φ6mm wire-wound type in dynamic environments. |
| Q4: Is it suitable for early monitoring of battery thermal runaway? Is the response timely enough? | A4: Very suitable. The low thermal inertia design allows the sensor to output a reliable signal within seconds of a sharp rise in battery surface or tab temperature, far superior to NTC or ordinary thermocouples. It has been adopted by multiple new energy vehicle BMS as a critical sampling component. |
| Q5: How to wire correctly to avoid measurement errors caused by lead resistance? | A5: Priority should be given to a three-wire system (two wires of the same color connected to one end, the third to the other end) to basically cancel the lead influence; highest precision uses a four-wire system to eliminate it completely. Avoid two-wire systems for long leads or high-precision situations; in actual testing, a three-wire system can control the error within 0.05°C. |
| Q6: How is the long-term drift of the sensor? How to verify stability? | A6: High-quality thin-film Pt100 has a drift of <0.04% after 1000 hours at 200°C, with an annual drift rate of 0.01–0.02%. Verification method: periodically use an ice point bath (0°C) and boiling point (100°C) or a standard constant temperature bath to verify the resistance value, and recalibrate or replace if it exceeds the standard. |
| Q7: How to prevent damage to thin-film elements during welding or SMT installation? | A7: It supports reflow/wave soldering, but the temperature at the base of the leads should not exceed 260°C for 10 seconds. Use heat sink clips to protect the sensing head, prioritizing spot welding or low-temperature tin; ceramic encapsulated types have better heat resistance, but avoid direct heating of the thin-film area. |
| Q8: Can it be used reliably in strong corrosion or ultra-high temperature environments? | A8: Standard 316L sheaths are suitable for general acid and alkali media; for ultra-high temperatures (>400°C), choose ceramic or special alloy sheaths. For strong corrosion scenarios, Hastelloy/Tantalum sheaths can be customized. Above 600°C, it is recommended to switch to a thermocouple solution to ensure lifespan. |
Summary
The Nexisense Pt100-CSMD platinum thin film resistance temperature sensor organically integrates the reliable precision of Pt100 with the fast response, miniaturization, and high durability of thin-film technology. It provides a practical and economical temperature measurement core for industry, new energy, household appliances, and precision measurement. As temperature control requirements become increasingly strict, choosing such a sensor can significantly improve system response speed, reduce maintenance costs, and provide a solid foundation for overall reliability. For complete specifications, sample testing, or customized solutions, please refer to the official Nexisense documentation or contact the technical team for further support.
