SHHW21-420 / SHHW21-600 Digital Triple-Function Electric Constant-Temperature Water Bath

Overview

The SHHW21-420 and SHHW21-600 Digital Triple-Function Electric Constant-Temperature Water Baths are precision-engineered thermal platforms designed for reproducible, stable liquid-phase temperature control in routine and research-grade laboratory environments. Operating on resistive heating principles with closed-loop PID feedback, these units maintain setpoint accuracy within ±0.5 °C across the full 37–100 °C operating range—optimized for applications requiring sustained thermal stability without mechanical agitation or forced convection. Unlike circulating water baths, the SHHW21 series functions as a static immersion bath, making it suitable for gentle sample warming, enzymatic incubation, serum equilibration, reagent preheating, and low-risk sterilization procedures such as boiling disinfection of glassware and instruments. The triple-function designation refers to its validated utility across three operational modes: constant-temperature holding, timed heating cycles, and open-bath boiling—each supported by independent safety logic and thermal cutoffs.

Key Features

• Microprocessor-based digital PID temperature controller with real-time display, adjustable setpoint resolution of 0.1 °C, and auto-tuning capability for consistent thermal response across ambient load variations
• Dual-chamber configuration options: compact SHHW21-420 (420 × 180 × 105 mm internal volume) for benchtop efficiency; extended SHHW21-600 (600 × 300 × 150 mm) for high-capacity vessel support including multiple flasks, beakers, or culture bottles
• High-purity 304 stainless steel interior tank and hinged lid—resistant to corrosion from aqueous buffers, saline solutions, and mild alkaline/acidic media commonly used in clinical and biochemical protocols
• Electrostatically applied powder-coated carbon steel outer casing—mechanically robust, non-reflective, and compatible with standard laboratory cleaning agents and wipe-down decontamination regimens
• Over-temperature protection circuitry with independent bimetallic thermal cut-off (110 °C nominal trip point) and ground-fault interrupter (GFI)-compatible power input
• Integrated water-level sensor with visual alarm indicator—prevents dry-run operation and heater element damage during extended unattended use

Sample Compatibility & Compliance

These water baths accommodate standard laboratory glassware—including Erlenmeyer flasks (up to 2 L), graduated cylinders, petri dish stacks, serological pipettes, and centrifuge tubes—without requiring custom fixtures or suspension racks. The flat, seamless tank bottom ensures uniform heat distribution and eliminates hot-spot formation near immersion elements. Units comply with IEC 61010-1:2010 safety requirements for electrical equipment used in laboratory settings and meet basic electromagnetic compatibility (EMC) Class B emission limits per CISPR 11. While not certified for ISO/IEC 17025 calibration traceability out-of-box, the digital controller supports external verification using NIST-traceable RTD probes (e.g., PT100), enabling labs to establish documented calibration intervals aligned with internal quality management systems. Routine operation aligns with Good Laboratory Practice (GLP) documentation standards when paired with logbook entries or electronic audit trails.

Software & Data Management

The SHHW21 series operates via embedded firmware with no proprietary software dependency. Temperature setpoints, elapsed time, and status alerts (e.g., low-water, over-temp) are displayed locally on a high-contrast LED interface. For integration into networked lab environments, optional RS-485 Modbus RTU output is available upon request—enabling connection to building management systems (BMS), centralized monitoring dashboards, or LIMS platforms supporting serial device polling. All operational events—including power-on reset, setpoint changes, and safety interlock triggers—are timestamped and retained in non-volatile memory for up to 72 hours, facilitating root-cause analysis during QA investigations. Data export requires manual transcription or third-party serial-to-CSV conversion tools; native USB or Ethernet connectivity is not included in base configuration.

Applications

• Clinical diagnostics: Serum sample thawing and equilibration at 37 °C prior to immunoassay processing
• Pharmaceutical QC: Dissolution medium conditioning per USP <711>, buffer pre-warming for HPLC mobile phase preparation
• Microbiology: Agar plate drying, antibiotic susceptibility test incubation, and glassware boiling sterilization in resource-constrained settings
• Academic research: Enzyme kinetics assays requiring precise thermal staging, DNA hybridization step incubations, and solvent evaporation under controlled conditions
• Industrial hygiene: Calibration of liquid-in-glass thermometers and validation of temperature-sensitive chemical storage conditions

FAQ

What is the maximum recommended fill level for safe operation?
The water level must remain ≥20 mm above the heating element—clearly marked inside the tank—and never exceed the overflow line located 15 mm below the top rim.
Can these units be used with organic solvents such as ethanol or acetone?
No. The SHHW21 series is rated exclusively for aqueous solutions. Organic solvents pose fire hazards and may degrade seals or contaminate the stainless steel surface.
Is external calibration possible, and what probe type is recommended?
Yes. A Class A PT100 RTD probe with 3-mm diameter sheath and 1-meter PTFE-insulated lead is recommended for field verification against the displayed setpoint.
Does the unit support programmable ramp-soak profiles?
No. It provides fixed-point temperature control only. Multi-step thermal profiles require external timer relays or programmable logic controllers (PLCs).
What maintenance is required to ensure long-term thermal stability?
Monthly descaling using 5% citric acid solution is advised for hard-water regions; annual inspection of gasket integrity and terminal block tightness is recommended per preventive maintenance schedules.