ZT Instruments' petroleum testing instruments strictly comply with international and domestic standards including ISO, ASTM, GB, and SH. For example, our Pour Point Tester is designed according to GB/T 3535, and our Diesel Total Contaminants Tester complies with GB/T 33400. Every instrument undergoes rigorous calibration and performance testing before delivery to ensure accurate, reliable, and traceable test data.

Taking ZT Instruments' ZT-S03C Petroleum Products Pour Point Tester as an example, it features a 4-hole testing unit and adopts compressor refrigeration. The cold bath temperature range is from -70°C to 80°C with a control accuracy of ±0.1°C. The cold bath temperature is controlled by an intelligent digital temperature controller with PID self-tuning function, ensuring precise temperature control and easy observation.

The ZT-D17 Diesel Total Contaminants Tester adopts an integrated structural design. Its core components include a single-stage rotary vane vacuum pump, stainless steel precision needle valve, and high-quality glass fiber filter device. The vacuum pump features coarse and fine adjustment functions, the suction flask is equipped with a grounding wire, and the instrument includes a timer for recording test time. The overall structure is well-designed and easy to maintain.

ZT Instruments has capabilities in product structure design, principle application and implementation, and software design and development. The company has a professional R&D team that can provide customized development based on users' specific testing requirements, meeting the individualized needs of customers in various industries such as refineries, lubricant plants, and power plants.

Dalian ZT Instrument Technology Co., Ltd. was founded in 2020 with a registered capital of 8 million RMB. It is a modern enterprise integrating R&D, production, sales, and service. The company has dozens of mature products and possesses advanced technical capabilities and R&D production capacity. Its products are mainly used in refineries, lubricant plants, power plants, steel mills, and fine chemical plants.

ZT Instruments has a professional after-sales service team responsible for instrument installation and commissioning, laboratory training, instrument maintenance, and repair services. The company always regards product quality and after-sales service as the life of the enterprise, and is committed to providing customers with comprehensive technical support and service guarantees.

Core physical and chemical analysis items for lubricants include: kinematic viscosity, water content, total acid number (TAN), total base number (TBN), insoluble content, oxidation stability, and flash point. In addition, spectral analysis can detect wear metal elements (iron, copper, aluminum, chromium, etc.) and additive elements (zinc, phosphorus, calcium, etc.), while ferrography analysis evaluates wear particle morphology and concentration.

There are two main methods for oil water content testing: the distillation method (GB/T 260) is suitable for constant water content determination; the Karl Fischer titration method (ASTM D6304) is suitable for trace moisture detection with accuracy up to ppm level, particularly suitable for transformer oil, lubricants, and other moisture-sensitive products. ZT Instruments provides complete water content testing solutions.

Oil contamination level is typically expressed according to the ISO 4406 standard. It is determined by detecting the number of particles in three size ranges — 4μm, 6μm, and 14μm — per unit volume of oil sample. For example, "18/16/13" represents particle concentration levels for different sizes. The testing equipment is an automatic particle counter, which uses the laser obscuration principle to quickly determine contamination level.

Marine fuel oil should be tested according to GB 17411 or ISO 8217 standards. Core compliance indicators include: sulfur content (IMO limit is 0.50%, 0.10% in emission control areas), kinematic viscosity, density, flash point, pour point, and total sediment. Distillate grades (DM) focus on cetane index, cloud point, and cold filter plugging point, while residual grades (RM) focus on viscosity, density, metal content, and carbon residue. ZT Instruments provides complete testing instrument solutions covering all the above indicators.

On-site oil testing uses portable instruments to deliver immediate results for parameters like viscosity, water content, and contamination levels, enabling quick maintenance decisions without sample transport delays. Laboratory oil analysis, by contrast, offers higher precision and a wider test scope—including trace element analysis by ICP or RDE-OES—but involves longer turnaround times. Many maintenance programs combine both: portable oil testing for routine screening and lab analysis for confirmatory or advanced diagnostics.

Proper sampling is critical for accurate oil testing. Samples should be drawn from a live, circulating system rather than from the bottom of a sump, where settled contaminants accumulate. Use clean, dry sample containers and flush the sampling valve before filling. For particle count testing, sample bottles must meet strict cleanliness standards to avoid false contamination readings. Poor sampling technique is one of the most common causes of misleading oil testing results.

FTIR (Fourier Transform Infrared) oil analysis is a spectroscopic technique used in oil testing to detect chemical changes in lubricants. It measures oxidation, nitration, additive depletion, and contamination from water, glycol, or soot by identifying specific molecular signatures in the oil. FTIR oil testing is valued because it requires minimal sample preparation and can assess multiple degradation parameters in a single measurement, making it suitable for both laboratory and portable oil analysis instruments.

Particle counting is a key oil testing method for hydraulic, turbine, and other precision fluid systems. It quantifies solid contaminants by size distribution and assigns a cleanliness code per standards such as ISO 4406 or NAS 1638. Elevated particle counts indicate filter failure, ingress contamination, or component wear, and can trigger maintenance action before damage occurs. Oil testing with a particle counter is often performed alongside viscosity and water content checks for a complete fluid condition assessment.

Oil testing is a cornerstone of predictive maintenance because it reveals equipment condition without disassembly. By trending parameters such as wear metal concentrations, viscosity changes, water ingress, and acid number, maintenance teams can schedule interventions based on actual oil and machine health rather than fixed intervals. This approach reduces unplanned downtime and extends both oil life and component life. Effective predictive maintenance programs typically combine routine on-site oil testing with periodic laboratory oil analysis for a complete picture.