Thermistor Signal Conditioning in Subsea Data Logging Systems
Pulsed ratiometric excitation and ultra-low tempco references eliminate subsea thermistor self-heating and hydrostatic drift down to millikelvin accuracy.
ITS-90 Scale
Meaning
Temperature measurements in science and industry require a highly reproducible reference system to ensure global consistency. This standard, officially called the ITS-90 Scale, defines the relationship between physical temperatures and measured electrical or thermodynamic values. It provides the legal and technical foundation for calibrating high-precision thermometric instruments used in manufacturing and transport.
Calibration Benchmark
Sensor accuracy across diverse markets depends on trace-ability to a single recognized benchmark. By specifying the ITS-90 Scale in purchase agreements, buyers of industrial thermometers ensure that different manufacturers supply sensors that yield identical readings. This agreement is critical in chemical processing and food logistics, where minor thermal variations can compromise product safety or contract compliance.
The standard enables precise cross-border comparison of thermal data.
Fixed Point
Thermometric calibration relies on the transition temperatures of pure substances under controlled conditions. These defining states, which include the triple point of water and the freezing points of various metals, provide highly stable reference temperatures. By measuring these physical phenomena, calibration laboratories align their instruments with the ITS-90 Scale.
This process eliminates instrument drift and ensures that commercial shipments of temperature-sensitive goods are monitored accurately.
Interpolation Method
Mathematical formulas are used to bridge the gaps between the fixed points of the standard. These equations convert sensor resistance or voltage readings into temperature values across the defined ranges. By applying these interpolation formulas, devices maintain high linearity and resolution.