ABOUT US · QUALITY & TRACEABILITY

Built for the hardest measuring points in industry.

Yuyao Jiyuan Instrument Co., Ltd. is a manufacturing enterprise founded in 2012, specialising in the research, custom design, production and sales of special-purpose thermocouples for demanding industrial applications.

WHO WE ARE

Application engineering, not catalogue selling

Our engineering team operates an in-house high-temperature laboratory and maintains long-term cooperation with several universities. Targeting severe service conditions in waste-to-energy plants, coal-fired power plants (CFB boilers), biomass power plants, steel mills, cement plants and carbon plants, we continuously test and develop protection-tube materials in close cooperation with site engineers.

Through years of development we have engineered a range of high-performance wear-resistant, corrosion-resistant and ultra-high-temperature thermocouples that overcome the short service life typical of conventional thermocouples in these positions. In particular we have achieved significant technical breakthroughs in the waste-to-energy furnace chamber and hold several patents covering furnace thermocouples, ultra-high-temperature thermocouples and wear/corrosion-resistant thermocouples.

Beyond thermocouples we also manufacture RTDs (Pt100), bimetallic thermometers, pressure gauges and a range of temperature transmitters — offering complete measurement solutions rather than a single product line.

Reference base: our sensors are in service at 150+ waste-to-energy and power plants across China, and are also used by metrology institutes, calibration laboratories and environmental test laboratories nationwide.
CERTIFICATIONS & QUALITY ASSURANCE

Everything your engineer needs to approve us

Certificate / reportScopeValidity / basis
ISO 9001:2015
Quality Management System
Design & manufacture of thermocouples, RTDs and stainless steel pressure gauges; sales of instruments Valid until 2029-07-08
ISO 14001:2015
Environmental Management System
Same scope as above Valid until 2029-07-08
ISO 45001:2018
Occupational Health & Safety
Same scope as above Valid until 2029-07-08
Product type-test reports
Sheathed thermocouples
Type WRNK series sheathed thermocouples Tested to GB/T 18404-2022 (equivalent to IEC 61515); tolerance basis GB/T 16839 (equivalent to IEC 60584-1). English version available on request.
Measurement standards certificate
Sheathed thermocouple calibration facility
Calibration of sheathed thermocouples, 300–1100 °C Issued under China Metrology Law; valid until 2028-03-28
Measurement standards certificate
Secondary standard Pt resistance thermometer
Calibration of industrial Pt100 / Cu resistance thermometers, −80 to +300 °C Valid until 2028-03-28
Patents (utility model, multiple) Furnace-dedicated thermocouple; ultra-high-temperature thermocouple; wear- and corrosion-resistant thermocouple Granted
After-sales service certification After-sales service capability, instruments & meters Valid
Calibration & traceability: each shipment can be supplied with calibration certificates covering thermocouples (K, S, N, E, J) and Pt100 / Pt1000 resistance thermometers, traceable through China's national measurement system. Where your procurement policy requires an independent third-party laboratory, testing and certification can be arranged with accredited laboratories in China at your designation.
NAMED TECHNOLOGY

The materials we developed, and what we call them

Each of these is a real, in-production protection-tube or sealing technology — tested on site until its service life was proven. We name them so you can specify them.

CrGuard™Austenitic high-temperature alloy with 40–65% chromium for hot strength, thermal-shock and wear resistance.
ClGuard™Anti-chlorine alloy for high-Cl flue gas — more than 6× the corrosion resistance of ordinary alloys.
HeatMax™High-temperature alloy reaching 1400 °C; the drop-in replacement for brittle alumina tubes in Type S service.
HardSurf™High-speed automated overlay welding with fine-grain transition — for combined corrosion and erosion duty.
CeramShield™Composite ceramic tube rated to 1600 °C, dense and low-porosity; will not burst under high/low cycling.
SealTight™Sealing process for metrology-grade RTDs — water and oil resistant, R0 drift under 0.15 °C after 672 h at temperature.
WHY CUSTOMERS CHOOSE JIYUAN

Four reasons, stated plainly

01

Application engineering, not catalogue selling

Protection-tube material and probe design are matched to your furnace type, fuel, flue-gas chemistry and installation point — then tested until the service life is proven on site.

02

Life-cycle thinking

For furnace sensors we quote expected service life by tube diameter and position, so you can budget replacement intervals instead of reacting to failures.

03

Verifiable quality chain

In-house metrology laboratory covering thermocouple and Pt100 calibration, product type-test reports, and a full quality / environment / occupational health & safety management system.

04

Custom is standard

Insertion length, diameter, thread or flange, cable length, termination and accuracy class are all made to order. Nothing is held as a shelf item.