Yamato BK/BA Series Precision Constant-Temperature Water Baths
| Brand | Yamato |
|---|---|
| Origin | Japan |
| Model Series | BK (Fixed-Setpoint) / BA (Programmable) |
| Internal Volume Options | 27 L, 42 L, 70 L, 109 L, 144 L |
| Temperature Range | Room Temp. +5°C to +80°C |
| Temperature Control Accuracy | ±0.02°C to ±0.07°C |
| Temperature Uniformity | ±0.1°C (within bath) |
| Heating Method | Nickel-Plated Copper Tubular Heater |
| Circulation | Integrated Magnetic Drive Circulator Pump |
| Controller | Microprocessor-Based PID with Dual Pt100 Sensors |
| Safety | Dual Overheat Protection (PID-Controlled Cut-off + Independent K-Type Thermocouple), Auto-Diagnostic System (Heater Open-Circuit, SSR Failure, Sensor Fault), Earth Leakage & Overcurrent Protection |
| Power Supply | 100–220 V AC, Single Phase, 50/60 Hz |
| Compliance | Designed for GLP-compliant laboratory environments |
Overview
The Yamato BK/BA Series Precision Constant-Temperature Water Baths are engineered for high-stability thermal conditioning of samples, calibration standards, and analytical instrumentation in regulated research, quality control, and pharmaceutical development laboratories. Utilizing a dual-sensor microprocessor PID control architecture with independent Pt100 platinum resistance thermometers and redundant K-type thermocouple-based overheat protection, these baths deliver exceptional thermal accuracy and long-term repeatability. The BK models operate in fixed-setpoint mode—ideal for routine incubation, viscosity standardization, or enzymatic reaction maintenance—while the BA series adds programmable multi-segment temperature profiles (up to 16 steps per program), enabling complex thermal ramping, hold-and-soak sequences, and automated cycling without external controllers. All units employ nickel-plated copper tubular heaters for rapid, uniform heat transfer and low-corrosion durability, coupled with magnetically coupled circulation pumps that eliminate seal wear and minimize contamination risk in extended-use applications.
Key Features
- Microprocessor PID temperature control with dual Pt100 sensors ensures ±0.02°C to ±0.07°C setpoint accuracy and ±0.1°C intra-bath uniformity across all volume classes.
- Independent, user-adjustable overheat protection circuit with K-type thermocouple monitoring provides fail-safe thermal shutdown, compliant with IEC 61010-1 safety requirements.
- Auto-diagnostic system continuously monitors heater integrity, solid-state relay (SSR) status, sensor continuity, and power supply anomalies—displayed via intuitive LED indicators.
- Large, tempered glass observation window (up to 440 × 265 mm) enables real-time visual monitoring without lid removal, minimizing thermal disturbance and evaporation loss.
- Stainless steel (SUS304) tank interior and corrosion-resistant nickel-plated heating elements ensure compatibility with aqueous buffers, saline solutions, and mild chemical media.
- Digital timer function supports automatic start/stop cycles from 1 minute to 999 hours 50 minutes—critical for unattended overnight stability testing or accelerated aging studies.
Sample Compatibility & Compliance
These water baths accommodate a broad range of sample formats—including glass and plastic immersion vessels, reference thermometer wells, viscometer spindles, and calibration blocks—without compromising thermal homogeneity. The absence of mechanical seals in the magnetic drive circulation system eliminates lubricant migration and reduces maintenance intervals, supporting continuous operation under ISO 17025-accredited quality management systems. Units meet CE marking requirements (2014/30/EU EMC Directive, 2014/35/EU LVD Directive) and are constructed to align with Good Laboratory Practice (GLP) documentation workflows. When paired with Yamato’s optional data logging interface or third-party validated software platforms, full electronic record retention—including temperature traces, alarm logs, and operator actions—meets FDA 21 CFR Part 11 electronic signature and audit trail mandates.
Software & Data Management
While the BK/BA series operates as a standalone instrument with front-panel digital interface, it features RS-232 and optional RS-485 communication ports for integration into centralized lab automation networks. Compatible with Yamato’s proprietary LabManager™ software (sold separately), users can remotely configure temperature ramps, export time-stamped CSV datasets, generate calibration certificates, and archive event logs—including overheat alarms, power interruptions, and sensor fault triggers. All logged parameters include UTC timestamps, user ID fields, and cryptographic hash verification to satisfy ALCOA+ data integrity principles (Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring, Available).
Applications
- Thermal calibration of liquid-in-glass thermometers, RTDs, and thermistors per ASTM E77 and ISO 17025 clause 6.5.2.
- Controlled-temperature incubation of cell cultures, microbial suspensions, and enzyme kinetics assays requiring stable ±0.05°C environments.
- Viscosity measurement support for rotational rheometers and capillary viscometers where bath temperature directly impacts shear rate accuracy.
- Accelerated stability testing of pharmaceutical formulations (ICH Q1A) and medical device materials per ISO 10993-12.
- Pre-conditioning of reference standards prior to DSC, TGA, or DMA analysis to eliminate thermal history effects.
- Constant-temperature equilibration of density meters, refractometers, and conductivity cells during method validation.
FAQ
What is the difference between BK and BA models?
The BK series operates exclusively in fixed-setpoint mode with manual temperature input, while the BA series supports programmable multi-step temperature profiles—up to two independent programs with 8 segments each, or one program with up to 16 segments.
Can these baths be used for oil or organic solvent immersion?
No. These units are designed strictly for aqueous media. Use only deionized water, buffer solutions, or glycerol-water mixtures below 80°C; avoid flammable, corrosive, or highly viscous liquids.
Is external calibration traceability available?
Yes. Yamato provides NIST-traceable calibration certificates (optional) covering temperature accuracy, uniformity, and stability at three points within the operating range, aligned with ISO/IEC 17025 accredited procedures.
How is temperature uniformity verified across large bath volumes?
Uniformity is validated using a 9-point grid mapping protocol (per ASTM E1112), with measurements taken at center, corners, and midpoints at three depths—ensuring compliance with ±0.1°C specification across the entire working zone.
What maintenance is required for long-term reliability?
Routine cleaning with mild detergent and periodic descaling (using 5% citric acid solution) every 3–6 months, depending on water hardness. Circulator pump impellers require inspection annually; no lubrication is needed due to magnetic coupling design.
