Yiheng MP-50C Refrigerated & Heated Circulating Bath

Overview

The Yiheng MP-50C Refrigerated & Heated Circulating Bath is an engineered thermal management system designed for precise, stable, and bidirectional temperature control in laboratory and analytical applications. Utilizing a dual-mode thermodynamic architecture—combining a high-efficiency hermetic compressor, Peltier-assisted pre-cooling (where applicable), resistive heating elements, and a high-head circulation pump—the MP-50C delivers consistent thermal output across its full operational range of –50 °C to +100 °C. Its 4.5 L stainless-steel bath reservoir supports both internal temperature stabilization and external heat exchange via integrated inlet/outlet ports compatible with standard 1/4″–3/8″ tubing. The unit operates under closed-loop PID control with real-time feedback from a calibrated Pt100 sensor immersed directly in the working fluid, ensuring thermal stability within ±0.1 °C at setpoint under static load conditions.

Key Features

• Microprocessor-based digital controller with large-backlit LCD display, enabling intuitive setpoint entry, real-time temperature readout, and status diagnostics.
• Imported hermetic scroll compressor delivering rapid cooldown from ambient to –40 °C in under 45 minutes (typical), with low acoustic emission (<58 dB(A)) and high energy efficiency (COP ≥ 2.3 at –20 °C).
• Dual-mode safety system: independent high-temperature cutoff (≥105 °C), low-temperature alarm (≤–52 °C), and level-sensing float switch to prevent dry-run operation of pump and heater.
• Externally controllable circulation pump with adjustable flow rate (0–12 L/min) and pressure head up to 0.35 bar—suitable for driving external jackets, reactors, or spectrometer cells.
• Robust stainless-steel construction (304 grade bath tank, powder-coated steel chassis) with insulated lid and splash-resistant front panel meeting IP20 environmental rating.
• Modular I/O expansion capability: optional RS-485 (Modbus RTU), USB host port (for U-disk data logging), and parallel printer interface compliant with IEEE 1284 standards.

Sample Compatibility & Compliance

The MP-50C is compatible with water, water–glycol mixtures (up to 50% v/v), silicone oils (cSt ≤ 500), and other non-corrosive, low-volatility heat-transfer fluids. It is not rated for use with flammable solvents, halogenated hydrocarbons, or strongly oxidizing agents. The unit complies with IEC 61010-1:2010 (Safety Requirements for Electrical Equipment for Measurement, Control, and Laboratory Use), EMC Directive 2014/30/EU, and RoHS 2011/65/EU. When operated with validated protocols and calibrated traceable sensors, it supports GLP-compliant thermal validation studies per ISO/IEC 17025 and ASTM E2877–22 (Standard Guide for Thermal Validation of Liquid Baths).

Software & Data Management

The optional Yiheng TempLog Suite (v3.2+) provides PC-based monitoring, programmable ramp-soak profiles, and audit-trail-enabled data acquisition. Time-stamped temperature logs (sampling interval: 1–300 s) are stored in CSV format with metadata including operator ID, calibration certificate number, and environmental ambient reading. The software supports 21 CFR Part 11–compliant user authentication, electronic signatures, and immutable record archiving when deployed on validated Windows OS platforms. All communication interfaces undergo CRC-16 error checking; firmware updates are performed via signed binary packages verified using SHA-256 hash integrity checks.

Applications

• Calibration of temperature-sensitive instrumentation (e.g., IR thermometers, RTD probes, thermocouple reference junctions).
• Thermal conditioning of optical components (lenses, detectors, interferometer arms) requiring sub-0.2 °C stability over 8+ hour periods.
• Controlled-rate cooling/heating for polymer crystallization kinetics studies (DSC sample prep, rheology pre-conditioning).
• Stabilized thermal environment for electrochemical cells, photovoltaic test fixtures, and microfluidic chip platforms.
• Support bath for rotary evaporators, vacuum ovens, and jacketed glass reactors requiring external coolant recirculation.

FAQ

What is the minimum recommended fluid volume for stable operation?
The bath requires ≥3.2 L of heat-transfer fluid to ensure adequate immersion of the sensor, heater, and evaporator coil while maintaining thermal homogeneity.
Can the MP-50C be used with silicone oil at 100 °C continuously?
Yes—when filled with Dow Corning 200 Fluid (50 cSt), continuous operation at 100 °C is permissible provided the external loop pressure remains below 0.3 bar and fluid oxidation is monitored per ASTM D92.
Is external temperature feedback supported for cascade control?
Not natively; however, the RS-485 interface allows integration with third-party PLCs or DAQ systems that can implement master–slave control logic using Modbus register mapping.
Does the unit include NIST-traceable calibration documentation?
Factory calibration certificates (as-found/as-left) are provided with each unit; NIST-traceable field calibration services are available through authorized Yiheng service centers under ISO/IEC 17025 accreditation.
What maintenance intervals are recommended for long-term reliability?
Compressor oil inspection every 18 months; condenser coil cleaning quarterly in dusty environments; annual verification of PID tuning parameters and sensor linearity per ASTM E74–21 Annex A2.