YIHENG MP-19H Precision Circulating Bath
| Brand | YIHENG |
|---|---|
| Origin | Shanghai, China |
| Manufacturer Type | Direct Manufacturer |
| Product Category | Domestic |
| Model | MP-19H |
| Instrument Type | Circulating Bath |
| Circulation Mode | Internal & External |
| Temperature Control | Heating-Only |
| Bath Volume | 22.5 L |
| Temperature Range | RT+5°C to 100°C |
| Input Power | 1050 W |
| Supply Voltage | AC 220 V, 50 Hz |
Overview
The YIHENG MP-19H Precision Circulating Bath is an engineered thermal management system designed for laboratory environments requiring stable, uniform, and controllable temperature conditions across extended operation cycles. Based on proven German-derived thermal architecture and refined through over two decades of domestic manufacturing experience, the MP-19H employs a robust heating-circulation principle—utilizing resistive heating elements coupled with a high-efficiency centrifugal circulation pump—to maintain precise setpoint stability within ±0.1°C (typical at 37°C, under static load). Its sealed bath chamber and dual-path fluid dynamics support both internal temperature homogenization and external heat transfer via pressurized outlet/inlet ports, making it suitable for applications ranging from calibration reference baths and viscometer thermostating to external reactor jacketing and sensor conditioning in analytical workflows.
Key Features
- Microprocessor-based PID temperature controller with backlit LCD interface, delivering ±0.05°C setpoint repeatability and real-time deviation monitoring.
- Integrated dual safety system: independent overtemperature/low-temperature audio-visual alarm circuitry and level-sensing protection to prevent dry-run operation and thermal runaway.
- Externally mounted pressure delivery pump (max. head: 4.5 m, flow rate: up to 12 L/min at 0.2 bar) enabling reliable temperature transfer to auxiliary equipment such as glass reactors, condensers, or spectrophotometer sample compartments.
- Dual-port hydraulic interface (G1/4″ BSP male threads) compatible with standard silicone or fluoropolymer tubing (ID 6–8 mm), supporting quick-connect coupling and leak-resistant sealing.
- Optional multi-segment programmable controller (7 programs × 9 steps each; time resolution: 1 minute; max step duration: 99 h 59 min) with ramp-hold profiles, scheduled power-on/off, and adjustable pump speed (30–100% PWM control).
- All critical components—including heating cartridge, circulation impeller, and temperature sensor—are sourced from Tier-1 European and Japanese suppliers to ensure long-term drift stability and corrosion resistance in aqueous and low-viscosity organic media.
Sample Compatibility & Compliance
The MP-19H operates exclusively with water, water-glycol mixtures (up to 30% v/v), and low-volatility silicone oils (viscosity ≤ 50 cSt at 25°C). It is not rated for flammable solvents, strong acids/bases, or particulate-laden fluids. The unit complies with IEC 61010-1:2010 for electrical safety in laboratory equipment and meets CE marking requirements for EMC (EN 61326-1) and low-voltage directives. While not certified for GMP/GLP-regulated production environments, its programmable logging capability (via optional RS485 interface and YIHENG LabLink software) supports audit-ready timestamped temperature traceability aligned with FDA 21 CFR Part 11 principles when paired with validated third-party data acquisition systems.
Software & Data Management
The optional YIHENG LabLink communication module enables bidirectional serial control (RS485, Modbus RTU protocol) for integration into centralized lab automation platforms. Users can remotely configure temperature setpoints, initiate/terminate programs, monitor real-time bath temperature and pump status, and export CSV-formatted logs with millisecond-resolution timestamps. When used with compliant PC-based SCADA software, the system supports electronic signature capture, user access levels (admin/operator), and change history tracking—facilitating alignment with ISO/IEC 17025 documentation requirements for calibration laboratories.
Applications
- Thermostating of rotational viscometers, densitometers, and refractometers in QC/QA labs (ASTM D445, ISO 3104, USP <841>).
- Temperature stabilization of optical cells in UV-Vis and FTIR spectroscopy systems.
- Calibration of platinum resistance thermometers (PRTs) and thermocouples against NIST-traceable references.
- Jacketed reactor temperature control in small-scale synthesis and enzymatic reaction studies.
- Accelerated stability testing of pharmaceutical formulations per ICH Q1A(R2) guidelines (e.g., 40°C/75% RH support via external humidity chamber linkage).
- Material property evaluation including coefficient of thermal expansion (CTE) measurements and polymer melt index conditioning.
FAQ
What is the maximum recommended operating temperature for continuous use?
The MP-19H is rated for continuous operation up to 95°C with water and up to 100°C for short-term (<2 h) validation runs. For prolonged service above 85°C, use deionized water with corrosion inhibitor to minimize scaling.
Can the MP-19H be used with ethylene glycol solutions?
Yes—up to 30% (v/v) aqueous ethylene glycol is compatible; higher concentrations increase viscosity and reduce heat transfer efficiency, requiring pump speed adjustment and extended equilibration time.
Is external temperature feedback supported?
No—the system relies on internal Pt100 sensor feedback only; external probe input is not available in standard configuration.
Does the unit include a drain valve?
Yes—a front-mounted brass drain valve with integrated shut-off allows complete bath emptying without disassembly.
What maintenance intervals are recommended?
Inspect and clean the heater surface and circulation filter every 6 months; replace the bath fluid annually or after 500 operational hours, whichever occurs first.
