Explore our flagship heavy-duty bimetal thermometers, electric contact switches, and precision pressure sensors engineered for global industrial applications.
Understanding the fundamental thermodynamic principles, mechanical force transfer, and metallurgy behind bimetallic temperature measurement.
At the heart of every bimetal thermometer lies a strip composed of two distinct metals bonded together (typically Invar alloy and Brass/Stainless Steel). Because each metal possesses a different coefficient of thermal expansion ($\alpha$), temperature variations cause one metal to expand faster than the other, forcing the strip to bend predictably toward the side with the lower expansion rate.
To translate linear bending into rotational pointer deflection within a narrow stem, the bimetallic strip is wound into a tight helical coil for direct-mount stem thermometers or a spiral coil for surface-mount units. The helical winding multiplies the total mechanical rotation while keeping the probe probe diameter compact (6mm to 10mm).
The lower end of the helical bimetal coil is fixed to the tip of the stainless steel protection stem, while the upper end is connected directly to a center shaft linked to the dial pointer. As heat transfers from the medium through the stem wall, the coil rotates, driving the pointer across a calibrated temperature scale with zero internal gear backlash.
The total angular deflection ($\theta$) of a helical bimetallic coil is directly proportional to the change in temperature ($\Delta T$), the strip length ($L$), and inversely proportional to strip thickness ($t$):
\theta = K \cdot \frac{(\alpha_1 - \alpha_2) \cdot L \cdot \Delta T}{t}
In industrial manufacturing, precision heat treatments are applied to stress-relieve the bimetal spring, ensuring long-term zero drift and maintaining Class 1.0 accuracy (ISO/EN 13190 standard) over hundreds of thousands of thermal cycles.
Why top-tier international EPC contract firms and OEM equipment builders source bimetal instruments directly from China factories.
Process units demand heavy-duty, explosion-proof electric contact bimetal thermometers (IP65/IP67 rated). Thermowells made of SS316L, Hastelloy, or Monel are paired with vibration-resistant liquid-filled dials (silicone oil) to withstand high pressure, corrosive vapors, and continuous mechanical pulsation.
Large-scale hydronic heating, chilling plants, and air distribution systems require robust, cost-effective bottom-mount or back-mount bimetal thermometers with adjustable union connections for easy installation and 360-degree viewing angle alignment.
Sanitary bimetal thermometers engineered with polished SS316L stems, Tri-Clamp process fittings, and hermetically sealed bezels enable full CIP/SIP (Clean-in-Place) washdown protocols without moisture ingress or fluid contamination risk.
| Procurement Parameter | Standard Market Offerings | Huzhou Accuracy Instrument Co., Ltd. Standards |
|---|---|---|
| Accuracy Class | Class 1.6 or Class 2.0 (±1.6% - 2.0% FS) | Class 1.0 High Precision (±1.0% Full Scale Range) |
| Stem Material | SS201 or Basic SS304 | 316L Stainless Steel / Heavy-wall Seamless Tube |
| Environmental Protection | IP54 Dust/Splash Proof | Hermetically Sealed IP65 / IP67 Weatherproof Structure |
| Customization Capabilities | Fixed Stem Lengths & Dial Ranges | Full OEM: Stem 50mm-2000mm, Dual Scales (°C/°F), Custom Logos |
| Quality Control Testing | Sampling Inspection (AQL 2.5) | 100% Thermal Calibration & Pressure Chamber Testing |
Huzhou Accuracy Instrument CO LTD is professionally engaged in the development, sales and service of industrial mechanical pressure gauges, bi-metal thermometers, SF6 manometer, pressure sensor. Products are widely used in various applications such as Mechanical Engineering, Chemical Engineering, Food Industry, Pharmaceutical, and high technology electric appliances.
Established over two decades ago, our pressure gauge manufacturing facility spans 3,000 square meters, equipped with advanced production lines and rigorous quality control systems. As an industry leader, we integrate innovation with precision engineering to deliver reliable measurement solutions for global clients.
R&D Department (20 specialists): Focuses on material innovation, smart sensor integration, and compliance with international standards (e.g., ISO, API).
Production Workforce (120 technicians): Utilizes automated assembly and laser calibration technologies to ensure product durability and accuracy.
Sales & Service Unit (15 professionals): Provides 24/7 technical support and customized solutions across 30+ countries.
Annual output exceeds 2 million units, covering industrial-grade gauges (e.g., stainless steel gauge, black steel gauge, shock-proof gauge, sf6 gauge, thermometer, pressure sensor) for oil/gas, HVAC, and pharmaceutical sectors.
Products exported worldwide, with certifications including ISO, SGS, and CE, earning recognition for corrosion resistance and ±0.5% precision options.
Our laboratory conducts 100% pressure cycle tests and environmental simulations, adhering to ISO 9001 and ISO 17025 standards.
Continuous improvement drives our reputation for "zero-leak" performance in extreme conditions, supported by a comprehensive one-year warranty across all product lines.
Integrating traditional mechanical bimetal movements with IIoT digital signal transmitters and hazardous location protection.
Combining local mechanical dial indication (which functions without external power) with an integrated 4-20mA HART analog or Modbus RS485 digital transmitter output for centralized SCADA integration.
Utilizing high-viscosity silicone fluid matrices and internal gearless pointer dampeners to eliminate dial flutter caused by nearby heavy compressors, turbines, or pump cavitation.
Heavy-duty electrical contact switches (single/double limit switch) designed with magnetic detents to prevent arcing, enabling direct actuation of relays, pumps, and emergency alarm horns.
We have long followed the concept of "reasonable price, accurate delivery, good quality" and several business management models to keep our production quality above the required benchmark under ISO9001:2008 certified.
Key specification parameters required when issuing OEM RFQs to Chinese instrumentation manufacturers.
Standard industrial dial sizes include 2.5" (63mm), 3" (80mm), 4" (100mm), and 6" (150mm). Casing materials available in 304 Stainless Steel or heavy-duty Black Painted Steel.
Choose between Bottom Direct Mount, Every-Angle Adjustable Stem, Back Direct Mount, or Remote Capillary configurations based on pipeline orientation.
Process connections engineered to international standards: 1/4" NPT/BSP, 1/2" NPT/BSP, M20x1.5, as well as customized male sliding unions or sanitary Tri-Clamps.
Standard measuring spans ranging from -50°C to +500°C (-60°F to +930°F). Custom dual scale printings with corporate logos available upon request.
Detailed technical answers to common engineering, installation, and procurement questions regarding bimetal thermometers.
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