Ningbo Scientz GH-30 High-Precision Circulating Water/Oil Bath Thermostatic Chamber

Overview

The Ningbo Scientz GH-30 is a high-precision, dual-mode (refrigeration and heating) circulating thermostatic bath engineered for laboratory environments requiring exceptional thermal stability and long-term operational reliability. Utilizing a closed-loop circulation architecture based on Couette-flow principles and precision PID feedback control, the GH-30 maintains a uniform, turbulence-minimized thermal field within its stainless-steel bath chamber. Its core function is to generate and sustain a precisely regulated liquid medium—water or silicone oil—across a wide operational range (+5 °C to +100 °C), enabling both internal sample immersion and external temperature control of auxiliary equipment (e.g., spectrophotometer cells, viscometer jackets, or calorimeter blocks). The system employs an environmentally compliant refrigerant (R134a or equivalent HFC blend), certified per ISO 5149 and aligned with EU F-Gas Regulation Annex I requirements. Critical components—including the hermetic compressor, platinum resistance thermometer (PT100), and magnetic drive circulation pump—are sourced from Tier-1 international suppliers to ensure mechanical longevity and metrological consistency.

Key Features

• High-stability temperature control with programmable setpoint resolution of 0.01 °C and real-time stability of ±0.005 °C (at 25 °C, no load) to ±0.02 °C (full load, 80 °C)
• Dual-circulation mode: user-selectable internal recirculation (for bath homogeneity) or external loop (for remote device temperature regulation via flexible silicone tubing)
• Adjustable flow rate (0–20 L/min) with digital pump speed control, supporting pressure-sensitive applications and minimizing cavitation risk
• Intelligent power management: configurable auto-restart after power interruption; user-defined default state (standby or active setpoint hold)
• Integrated timer function with up to 999-hour countdown; automatic shutdown upon completion with audible alert and status flag
• Microprocessor-based controller with LCD interface, RS232/RS485 communication port, and optional analog 4–20 mA output for SCADA integration

Sample Compatibility & Compliance

The GH-30 accommodates standard laboratory vessels (up to Ø180 mm diameter) and supports immersion of probes, sensors, calibration standards, and small reactors. Its bath volume (≈30 L, derived from 400 × 330 × 230 mm internal dimensions) complies with ASTM E645–22 guidelines for thermal uniformity testing in liquid baths. All wetted parts are electropolished 304 stainless steel, ensuring chemical resistance to aqueous buffers, ethanol, and common organic solvents (excluding strong oxidizers or halogenated hydrocarbons above 60 °C). The unit meets CE marking requirements under the EU Machinery Directive 2006/42/EC and Electromagnetic Compatibility Directive 2014/30/EU. For GLP/GMP-regulated environments, audit-trail-capable firmware (v3.2+) supports 21 CFR Part 11-compliant electronic records when paired with Scientz’s optional LabControl Suite software.

Software & Data Management

The GH-30 supports bidirectional serial communication (ASCII protocol) for remote parameter setting, real-time temperature logging, and alarm event capture. When connected to Scientz LabControl Suite (Windows-based, .NET 6), users gain access to time-stamped data export (CSV/TXT), multi-channel trend visualization, deviation reporting against reference standards (e.g., NIST-traceable PRTs), and customizable validation protocols. Firmware updates preserve all user configurations and support secure authentication via encrypted firmware signature verification. Data logs include timestamp (ISO 8601), bath temperature, setpoint, pump speed %, compressor duty cycle, and error codes—enabling full traceability per ISO/IEC 17025:2017 Clause 7.7.

Applications

• Primary and secondary calibration of thermometers, RTDs, thermocouples, and infrared sensors per ISO 17025-accredited procedures
• Thermal conditioning of optical components during spectroscopic alignment and refractive index measurements
• Stabilization of detector housings in HPLC autosamplers and GC detectors to minimize baseline drift
• Controlled-temperature reaction monitoring in kinetic studies (e.g., Arrhenius parameter determination)
• Material property testing—including coefficient of thermal expansion (CTE) of polymers and thermal conductivity of nanofluids—per ASTM D7896 and ISO 22007-2
• Cell culture incubator validation and bioreactor jacket temperature profiling in pharmaceutical process development

FAQ

What is the maximum recommended working temperature when using silicone oil as the bath medium?
The GH-30 supports silicone oil operation up to 100 °C; however, continuous use above 80 °C requires oil with flash point >200 °C and periodic viscosity checks per ASTM D445.
Does the GH-30 support external temperature feedback control (e.g., from a probe placed in a reactor)?
Yes—via optional external sensor input (Pt100, 2-wire), enabling cascade control where the bath regulates based on the remote probe’s reading.
Is the unit compatible with networked lab infrastructure (e.g., Ethernet or Modbus TCP)?
Native Ethernet or Modbus TCP is not built-in; however, third-party protocol converters (e.g., Moxa NPort) can bridge RS485 to TCP/IP with minimal latency impact on control loop stability.
How often should the refrigerant charge be verified for optimal thermal performance?
Under normal operation, refrigerant integrity is validated during annual preventive maintenance; pressure readings and subcooling/superheat margins should align with factory specifications in the service manual (Rev. 4.1+).
Can the GH-30 maintain stability at 5 °C in ambient conditions exceeding 35 °C?
Yes—the system’s condenser cooling capacity (rated at 35 °C ambient) ensures stable operation down to +5 °C even under elevated room temperatures, provided adequate ventilation (>15 cm clearance on all sides) is maintained.