Siji Tonghui (Xi'an) Trading Co., Ltd.: Your Professional Instrument Manufacturer
Sijitonghui (Xi’an) Trading Co., Ltd. is a professional supplier of industrial components, including machine tools, precision bearings, instruments, and valves. With a strict supplier evaluation system and strong market knowledge, we ensure consistent product quality and compliance with international standards. Our global logistics network supports efficient delivery to over 30 countries, with an annual trade volume of USD 80 million.
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![Heat Sensitive Resistor]()
Heat Sensitive ResistorAs contact-type primary temperature measurement instruments, thermocouples and heat sensitive resistors (Resistance Temperature Detectors, RTDs) are core components for industrial temperature -
![Industrial Bimetallic Thermometers]()
Industrial Bimetallic ThermometersIndustrial bimetallic thermometers are professional on-site detection instruments specifically designed for medium and low-temperature measurement in industrial environments. Leveraging the principle -
![Smart Temperature Transmitter]()
Smart Temperature TransmitterOur Smart Temperature Transmitter stands as a cornerstone of accurate temperature monitoring, engineered to deliver consistent performance across the most demanding industrial environments. At its -
![High Accuracy Digital Pressure Gauge]()
High Accuracy Digital Pressure GaugePrecision pressure gauges are primarily used to calibrate general pressure gauges or to precisely measure the pressure and negative pressure of liquids, gases, or vapors that do not corrode copper, -
![Floating Ball Pressure Gauge]()
Floating Ball Pressure GaugeA float-type pressure gauge is a pressure reference instrument that uses nitrogen or instrument-grade (purified) compressed air as its energy source. It outputs accurate pressure signals and is an -
![Piston Pressure Gauge]()
Piston Pressure GaugeAs the cornerstone of precision pressure measurement, our Piston Pressure Gauge stands as an indispensable reference instrument for laboratories, metrology rooms, and quality control centers -
![Differential Remote Pressure Gauge]()
Differential Remote Pressure GaugeWhen industrial processes demand precise pressure measurement amid violent vibrations, high temperatures, and corrosive media, the Differential Remote Pressure Gauge stands as the unmatched solution. -
![Corrosion-resistant Diaphragm Pressure Gauge]()
Corrosion-resistant Diaphragm Pressure GaugeThe stainless steel corrosion-resistant and shock-resistant diaphragm pressure gauge has good corrosion resistance to the measured medium and environment, and good shock resistance to environmental -
![Integrative Temperature Transmitter]()
Integrative Temperature TransmitterIt is usually used in conjunction with display instruments, recording instruments, electronic computers, etc., with a 4～20mA output. This product directly measures the temperature of liquid, steam, -
![Thermal Comfort Bimetallic Thermometer]()
Thermal Comfort Bimetallic Thermometer•Temperature measurement range: -80°C to +500°C, covering most industrial scenarios. •Accuracy class: 1.0 and 1.5, compliant with JJF1908—2021 calibration standard. •Protection class: IP55, -
![Bimetallic Thermometer with Electrical Contacts]()
Bimetallic Thermometer with Electrical ContactsAs a core instrument for industrial temperature measurement and control, the Bimetallic Thermometer with Electrical Contacts is designed based on the bimetallic strip thermal expansion principle, -
![End Face Thermocouple]()
End Face Thermocouple•High precision with Class A/B accuracy rating for reliable data acquisition. •Ultra-fast thermal response time <5s, capturing end-face temperature instantly. •Specialized wire-wound sensing element
why choose us
Strict supplier selection
We work only with qualified manufacturers using advanced and automated production systems, ensuring stable quality and reliable performance for every order.
Complete supply chain support
From sourcing and quality control to customs clearance and international shipping, we provide a full-service solution to reduce your procurement complexity.
Global delivery capability
With an established logistics network and warehouse coordination, we ensure timely delivery and flexible shipping solutions across multiple regions.
Experienced trade team
Our specialized regional teams understand local market requirements, enabling clear communication and efficient handling of international business needs.
The Instruments Manufactured By Our Company Primarily Fall Into the Following Types:
Heat sensitive resistor
As contact-type primary temperature measurement instruments, thermocouples and heat sensitive resistors (Resistance Temperature Detectors, RTDs) are core components for industrial temperature monitoring and control. These sensors operate by directly contacting the measured medium, converting temperature variations into detectable signals that integrate seamlessly with display, recording, and regulation instruments.
Piston pressure gauge
As the cornerstone of precision pressure measurement, our Piston Pressure Gauge stands as an indispensable reference instrument for laboratories, metrology rooms, and quality control centers worldwide. Engineered to calibrate precision pressure gauges, pressure sensors, and transmitters with unparalleled reliability, it sets the benchmark for accuracy in pressure metrology across industries.
Benefits of Instrument
Heat sensitive resistor
Compact size: Packaging options allow them to operate in small or tight spaces, thereby taking up less real estate on printed circuit boards.
Fast response time: The small dimensions allow for a quick response to change in temperature, which is important when immediate feedback is required.
Cost efficient: Not only are thermistors less expensive than other types of temperature sensors, if the purchased thermistor has the correct RT curve, no other calibration is necessary during installation or over its operational life.
Point match: The ability to obtain a specific resistance at a particular temperature.
Curve match: Interchangeable thermistors with the accuracy of +0.1˚C to + 0.2˚C.
Piston pressure gauge
Accuracy and precision: Piston pressure gauges are engineered for unmatched accuracy and precision in pressure measurement. Unlike digital or analog dial gauges that can drift over time or suffer from calibration errors, piston gauges use a physical equilibrium between applied pressure and calibrated weights to determine pressure values. This primary standard method minimizes measurement uncertainty and eliminates electronic interference, ensuring repeatable and traceable results.
High durability and reliability: Constructed from high-grade materials like stainless steel, hardened alloys, and corrosion-resistant coatings, piston pressure gauges are built to endure extreme operating conditions. They maintain performance under high temperatures, mechanical vibrations, and fluctuating pressure cycles—common challenges in industrial environments.
Wide pressure range: One of the standout features of piston pressure gauges is their ability to measure pressures across an exceptionally broad spectrum—from vacuum levels to ultra-high pressures exceeding 100,000 psi (6,895 bar), depending on the model and configuration.
Easy installation and user-friendly operation: Most piston pressure gauges are designed for straightforward integration into existing systems. Standard threaded connections (e.g., NPT, BSP, or metric threads) allow quick attachment to pipelines, manifolds, or test benches without requiring complex modifications.
Cost-effectiveness over time: Although the initial investment in a piston pressure gauge may be higher than that of standard analog or digital gauges, their long-term value is significant. With minimal wear and tear, low maintenance requirements, and decades-long service life when properly cared for, they offer a superior return on investment.
Application of Instrument
Heat sensitive resistor
HVAC systems
Thermistors play a crucial role in heating, ventilation, and air conditioning (HVAC) systems by enabling precise temperature monitoring and control. NTC thermistors are commonly used to measure air and refrigerant temperatures at key points within the system, such as evaporator and condenser coils.
Battery management in electric vehicles
In electric vehicles (EVs), battery management systems (BMS) rely heavily on thermistors to monitor the temperature of lithium-ion battery packs. Even minor deviations in cell temperature can impact performance, safety, and battery longevity.
Medical devices
Precision temperature measurement is essential in medical diagnostics and treatment, and thermistors excel in this domain due to their high accuracy and rapid response. They are widely used in digital thermometers, patient monitors, incubators, dialysis machines, and blood analyzers.
Industrial process control
In industries such as chemical manufacturing, pharmaceuticals, food and beverage, and plastics, precise temperature control is paramount for product quality, safety, and regulatory compliance. Thermistors are deployed throughout production lines to monitor reactors, ovens, sterilizers, and storage units.
Consumer electronics
Modern consumer electronics—including smartphones, laptops, gaming consoles, and home appliances—are densely packed with heat-generating components such as CPUs, GPUs, and power supplies. Thermistors are strategically placed to monitor hotspots and prevent thermal damage.
Emerging and niche applications
Beyond traditional uses, thermistors are finding new roles in emerging technologies. In renewable energy systems, they monitor inverter and solar panel temperatures to maximize efficiency and prevent degradation.
Piston pressure gauge
Oil and gas industry
From upstream extraction to downstream refining and distribution, precise pressure control is vital. Piston pressure gauges are used to calibrate and monitor pressure in pipelines, storage tanks, and processing equipment handling crude oil, natural gas, and refined products.
Manufacturing industry
In industrial manufacturing, especially in hydraulic and pneumatic systems, maintaining optimal fluid pressure is crucial for machine efficiency and product quality. Piston pressure gauge kits are used to monitor and calibrate presses, injection molding machines, CNC tools, and automated assembly lines.
Chemical industry
The chemical sector relies on tightly controlled reactions, many of which occur under high pressure. Piston pressure gauges monitor and calibrate pressure in reactors, distillation columns, and transfer lines carrying volatile or corrosive substances.
Aerospace industry
Safety and precision are non-negotiable in aerospace. Piston pressure gauges are employed to test and calibrate critical aircraft systems including landing gear hydraulics, brake systems, fuel delivery, and environmental control systems.
HVAC systems
In heating, ventilation, and air conditioning systems, proper refrigerant pressure is key to efficiency and performance. Piston pressure gauges are used during installation, servicing, and troubleshooting of residential, commercial, and industrial HVAC units.
Packaging and Shipping
FAQ
As one of the leading instrument manufacturers and suppliers in China, we also support customized service. Please feel free to wholesale high quality instrument at competitive price from our factory. For pricelist, contact us now.
