Digital Display Constant-Temperature Oil Bath

Overview

The CZGY HH-SK Digital Display Constant-Temperature Oil Bath is a precision thermal platform engineered for stable, uniform conductive heating of samples immersed in silicone oil or other high-boiling-point heat-transfer media. Operating on the principle of resistive immersion heating with digital PID-based temperature regulation, it delivers reliable thermal control across a wide range from ambient temperature up to 299 °C—making it suitable for applications requiring elevated thermal stability beyond the limits of standard water baths. Constructed entirely from 304 stainless steel, the bath vessel resists oxidation and chemical degradation under prolonged exposure to hot oils, ensuring long-term dimensional integrity and minimal contamination risk. Its compact footprint (Ø240 mm × 140 mm) supports benchtop integration in QC labs, synthetic chemistry workstations, polymer processing validation, and materials testing environments where precise, non-circulating thermal conditioning is required.

Key Features

• Stainless Steel Construction: Seamless 304 SS tank with polished interior surface minimizes oil residue accumulation and facilitates cleaning between batches.
• Digital PID Temperature Controller: Features intuitive push-button interface (SET, Δ, ▽) for setpoint entry and real-time display of actual bath temperature; includes adjustable proportional band (P), integral time (I), and derivative time (D) parameters for fine-tuned thermal response tuning.
• Thermal Stability & Resolution: Maintains ±1 °C stability at setpoint across full operating range; 1 °C resolution enables repeatable method setup per SOP-defined protocols.
• Safety-Centric Design: Includes over-temperature alarm (AL parameter configurable up to full scale), relay hysteresis (HY) to suppress contact chatter, and mandatory oil-level interlock logic enforced via operational guidelines (oil must cover heater by ≥20 mm prior to power-on).
• Energy-Efficient Operation: 1200 W heating element optimized for rapid thermal ramping and low standby power draw; no circulation pump reduces electrical load and mechanical failure points.

Sample Compatibility & Compliance

The HH-SK accommodates standard laboratory glassware including round-bottom flasks (up to 1 L), reaction tubes, sample vials, and metal crucibles—provided external dimensions fit within the bath’s internal cavity. It is compatible with common heat-transfer fluids such as silicone oil (e.g., Dow Corning 200 Fluid), mineral oil, and glycerol-based media. While not certified to ISO/IEC 17025 or ASTM E2234 for metrological traceability, its performance aligns with national verification requirements specified in JJG 205–2005 (Calibration Specification for Liquid Immersion Thermostats) and general-purpose thermal equipment acceptance criteria per GB/T 28001. The unit supports GLP-aligned documentation practices through user-configurable alarm thresholds and parameter locking (LCK=2 disables all internal settings except setpoint), mitigating unintentional deviation during routine operation.

Software & Data Management

This model operates as a standalone analog-digital hybrid instrument without embedded data logging or PC connectivity. All operational parameters—including setpoint, AL (alarm limit), HY (hysteresis), P/I/D tuning constants, SC (sensor offset), and LCK (parameter lock state)—are retained in non-volatile memory after power cycling. While it does not support FDA 21 CFR Part 11-compliant electronic records, its manual configuration workflow meets basic audit requirements for non-regulated research and teaching laboratories. For regulated environments requiring electronic audit trails, third-party USB data loggers with thermocouple inputs may be integrated externally using the bath’s exposed RTD sensor output terminals (available upon request with optional probe extension kit).

Applications

• Controlled-temperature reactions in organic synthesis (e.g., esterification, condensation, Grignard initiation)
• Viscosity measurement pre-conditioning of polymer melts and lubricants prior to rheometer loading
• Accelerated aging studies of packaging materials and adhesives per ASTM D3045
• Calibration of thermometers and temperature sensors using fixed-point oil baths
• Sample equilibration for differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)
• Seed germination and plant tissue culture incubation requiring supra-ambient but sub-boiling conditions

FAQ

What is the minimum safe oil level before powering on the bath?
The heating element must be fully submerged with at least 20 mm of oil above its upper surface. Operating below this level risks irreversible damage to the heater and voids warranty coverage.
Can I use water instead of oil in this bath?
No. The HH-SK is rated for temperatures up to 299 °C and lacks anti-boilover safeguards required for aqueous operation above 100 °C. Use only thermally stable, non-volatile oils approved for continuous duty at target temperature.
How do I correct a consistent temperature offset shown on the display?
Access the SC (sensor correction) parameter via 3-second SET key press, then adjust using Δ/▽ keys within the range of –50 °C to +50 °C. Confirm exit with another 3-second SET press.
Is the temperature controller programmable for ramp-soak profiles?
No. This unit provides single-setpoint on/off control only. For multi-step thermal protocols, external programmable controllers or PLC-integrated systems are recommended.
Does the unit include a grounding terminal?
Yes. A dedicated grounding screw is located on the rear panel. Proper grounding to an earth-grounded outlet is mandatory for operator safety and electromagnetic noise suppression.