MKN W-201B Digital Display Constant-Temperature Water Bath

Overview

The MKN W-201B Digital Display Constant-Temperature Water Bath is a precision-engineered benchtop thermal conditioning instrument designed for stable, reproducible liquid-phase temperature control in routine laboratory environments. It operates on the principle of convective heat transfer via a far-infrared heating element immersed in a thermally buffered stainless steel water reservoir, enabling rapid thermal equilibrium and minimal spatial temperature gradients across the bath chamber. Unlike open-heating plate systems, the W-201B’s fully enclosed circular chamber minimizes evaporative loss and ensures consistent thermal loading for vessels placed directly into the water medium. Its operational range—from ambient +5°C up to 100°C—covers the majority of standard biochemical incubation, solvent evaporation, enzymatic reaction activation, and sample pre-conditioning protocols. The unit is not intended for sterilization or pressurized applications, nor does it meet IEC 61010-1 requirements for hazardous location use; it is classified as Class I, Pollution Degree 2 equipment per EN 61010-1.

Key Features

• Single-well stainless steel circular chamber (Ø260 mm × 160 mm H) fabricated from imported 304-grade stainless steel for long-term corrosion resistance and thermal stability
• Far-infrared heating system delivering uniform thermal distribution with typical thermal equilibration time of ≤12 minutes (from 25°C to 60°C, load: 5 L water)
• Dual-integration high-precision A/D converter paired with low-drift operational amplifier circuitry for robust analog signal processing and minimized thermal drift in setpoint maintenance
• LED-based digital display providing real-time readout of actual bath temperature with 0.1°C resolution and ±0.3°C factory-calibrated accuracy at 37°C and 60°C
• Microprocessor-based proportional-integral (PI) temperature regulation algorithm ensuring steady-state deviation within ±1.0°C over 8-hour continuous operation
• Front-panel tactile controls with dedicated power switch, temperature setting knob, and status indicator—no software dependency or external interface required

Sample Compatibility & Compliance

The W-201B accommodates standard laboratory glassware including Erlenmeyer flasks (up to 2 L), beakers (up to 1 L), test tubes (in rack configuration), and sample vials immersed directly in the water medium. Its open-bath geometry supports passive convection-driven heat transfer and is compatible with floating lids or custom insulating covers to reduce evaporation during extended runs. While not certified to UL or CE for medical device use, the unit conforms to general safety expectations outlined in ISO 15195:2018 (laboratory calibration infrastructure) and supports GLP-compliant documentation when integrated into validated SOPs. It is routinely deployed in QC laboratories performing USP environmental monitoring prep, ASTM D129-18 (petroleum product evaporation testing), and ISO 5725-2:2019 repeatability assessments where controlled ambient-equivalent thermal conditioning is required.

Software & Data Management

The W-201B is a standalone analog-digital hybrid instrument with no embedded firmware update capability, network connectivity, or data logging functionality. All operational parameters are set and monitored locally via the front-panel LED interface. For laboratories requiring audit-trail compliance (e.g., FDA 21 CFR Part 11 or ISO/IEC 17025), users must implement external validation protocols—including independent thermometer verification at three points (center and two diagonally opposite positions) prior to each qualification cycle—and maintain manual logbooks or LIMS-integrated entry templates. No proprietary drivers, SDKs, or PC software are supplied or supported.

Applications

• Controlled-rate solvent evaporation in analytical sample preparation workflows (e.g., LC-MS extract concentration)
• Temperature-dependent solubility studies of pharmaceutical excipients and active ingredients
• Pre-incubation of culture media and reagent solutions prior to microbiological assays
• Accelerated aging tests for polymer film stability per ISO 11341:2019
• Calibration support for liquid-in-glass thermometers and RTD probes using fixed-point reference baths
• Thermal conditioning of viscosity standards prior to rotational rheometry measurements

FAQ

Is the W-201B suitable for use with organic solvents such as acetone or chloroform?

No. The bath is designed exclusively for aqueous media. Organic solvents may degrade seals, corrode internal components, and pose fire hazards due to their low flash points.
Can the unit maintain temperature accuracy under continuous 24/7 operation?

Yes—provided ambient room temperature remains between 15–30°C and relative humidity stays below 70% RH. Long-term stability testing shows drift ≤±0.8°C over 168-hour cycles when operated at 60°C.
Does the W-201B include overtemperature protection?

Yes. A redundant mechanical thermostat interrupts power if internal temperature exceeds 105°C, preventing dry-run damage.
What calibration documentation is provided?

A factory calibration certificate (traceable to NIM China) is included, covering verification at 37°C, 60°C, and 95°C using a calibrated Pt100 reference probe.
Is the stainless steel chamber electropolished or passivated?

The chamber undergoes acid passivation per ASTM A967-22 Method A to enhance oxide layer integrity and minimize metal ion leaching in ultrapure water applications.