Platinum resistive thermometer WZPB-2

°Cfor temperature calibrationindustrial

Product overview
The WZPB-2 Standard Platinum Resistance Thermometer (SPRT) by YUNYI is a metrological reference instrument designed to disseminate the International Temperature Scale (ITS-90). It is used as a reference for verification and calibration of standard mercury thermometers, industrial PRTs/CRTs and precision thermometers, and for direct high-accuracy temperature measurements in laboratory and industrial settings.

Fixed-point and construction
"Zinc Point" indicates calibration at the zinc fixed point (419.527°C). The sensing element is enclosed in a high-purity quartz sheath that provides excellent electrical insulation, chemical resistance and thermal stability at elevated temperatures.

Intended use & applications

• Primary function: Metrological reference for transferring ITS-90 and for thermometer verification/calibration.
• Typical users: Calibration laboratories, R&D facilities, industrial quality-control departments and national metrology institutes.

Typical application areas:

• Verification of standard mercury thermometers
• Calibration of industrial platinum resistance thermometers (PRTs)
• Calibration of industrial copper resistance thermometers (CRTs)
• Verification of precision thermometers and sensors
• Direct high-accuracy temperature measurement in experiments and controlled processes

Technical specifications (indicative)

• Model: WZPB-2
• Type: Second-Class Standard Platinum Resistance Thermometer (SPRT)
• Fixed point: Zinc point (419.527°C) — quartz sheath construction
• Sheath material: Quartz (high-purity silica)
• Temperature range: [ ] °C (example ranges shown on manufacturer page: e.g., -200 to +420°C; exact range unspecified)
• Resistance at 0°C (R₀): [ ] Ω (typical options: 25 Ω or 100 Ω; exact value unspecified)
• Temperature coefficient (α): [ ] (typically ≈ 0.003925 Ω/Ω/°C; exact value unspecified)
• Accuracy class: Grade II (Second-Class Standard)
• Long-term stability: [ ] °C/year (example: ≤ 0.01°C/year; exact value unspecified)
• Insulation resistance: ≥ [ ] MΩ (room temperature; example >100 MΩ)
• Measurement current: [ ] mA (typical example: 1 mA to minimize self-heating)
• Sheath outer diameter / length / overall length / connection type: [ ] (not specified on page; e.g., 4-wire connection common)

Construction & design features

• Platinum sensing element: High-purity platinum wire wound in a strain-free configuration to meet ITS-90 purity and stability requirements.
• Quartz sheath: High-purity silica sheath providing electrical insulation, chemical inertness and resistance to thermal shock; allows visual inspection of the element.
• Four-wire connection: Eliminates lead resistance errors and enables high-accuracy resistance measurements.
• Laboratory-grade construction: Suitable for immersion in calibration baths (water, oil, salt, sand) and designed for long-term stability under proper use.

Applicable standards & regulations

• ITS-90 — International Temperature Scale of 1990
• IEC 60751 — Industrial platinum resistance thermometers (reference characteristics)
• JJG 160 — Chinese national verification regulation for SPRTs

Included in standard delivery

• WZPB-2 Standard Platinum Resistance Thermometer (quartz sheath)
• Factory calibration certificate (typically including fixed-point calibration data)
• Protective storage case
• Instruction manual (Chinese / English available)

Operation & care guidelines
Before use:

• Inspect quartz sheath for cracks, chips or contamination.
• Check insulation resistance if a megohmmeter is available (manufacturer example suggests >100 MΩ at room temperature).
• Ensure correct immersion depth — typically ≥15–20× sheath diameter to reduce stem conduction errors.
• Connect using a 4-wire configuration to avoid lead resistance errors.

During use:

• Handle with care — quartz is fragile and may break if dropped or struck.
• Avoid thermal shock by applying gradual temperature changes.
• Use protective tubes in chemically aggressive or harsh environments.
• Do not exceed the rated maximum temperature to prevent permanent shifts in resistance characteristics.
• Use the specified measurement current (typical: 1 mA) to minimize self-heating.

After use:

• Clean the sheath with a soft, lint-free cloth; remove residues with a mild solvent compatible with quartz if necessary.
• Store the instrument in its protective case in a clean, dry, vibration-free location.
• Avoid contact with hard surfaces — scratches can affect performance.

Periodic maintenance

• Annual verification against fixed-point cells (zinc, tin, triple point of water) to confirm stability.
• Annealing procedures may be required after high-temperature exposure (consult manufacturer documentation).
• Recalibration by an accredited laboratory every 1–2 years depending on usage frequency.

Notes
Some numerical parameters on the original manufacturer page are presented as placeholders and are not specified numerically; confirm exact sheath dimensions, R0 value, measurement current and temperature range with the supplier prior to purchase.