HopeBio GH-ZLR01 Gravimetric Dilutor

Overview

The HopeBio GH-ZLR01 Gravimetric Dilutor is an engineered laboratory instrument designed for precise, repeatable, and traceable liquid handling in microbiological, pharmaceutical, and food safety testing workflows. Unlike volumetric dilutors that rely on fixed-displacement pumps or syringes, the GH-ZLR01 employs a gravimetric principle: it continuously monitors mass change during dispensing using a calibrated high-resolution load cell, enabling real-time feedback control of peristaltic pump operation. This closed-loop mass-based strategy eliminates cumulative errors from viscosity, temperature-induced density shifts, or tubing compression fatigue—critical for regulatory-compliant sample preparation where accuracy across matrix types (e.g., viscous homogenates, buffered suspensions, or low-surface-tension solvents) must be maintained. The system supports both serial dilution protocols and single-step proportional dilutions, making it suitable for ISO 7218, ISO 6887, USP , and AOAC-approved microbial enumeration methods.

Key Features

• Gravimetric feedback control architecture ensures ≤ ±1% volumetric accuracy across the full 20–4000 mL range, validated per ISO/IEC 17025 calibration practices.
• High-flow peristaltic pump delivers up to 2000 mL/min—optimized for rapid processing of large-volume samples such as food homogenates or environmental water concentrates.
• Motor-driven oscillating dispensing nozzle with programmable angular positioning enables seamless transition between container types without manual repositioning.
• Vertically adjustable dispensing height (manually operated via ergonomic single-hand lift) accommodates standard stomacher bags, open-top beakers, graduated cylinders, and ISO-certified dilution tubes.
• Stainless steel 304 chassis meets GMP-grade surface finish (Ra ≤ 0.8 µm) and corrosion resistance requirements for cleanroom and controlled environment use.
• Integrated autoclavable silicone tubing path (rated for 121 °C, 20 min steam sterilization) supports aseptic transfer and eliminates carryover risk in sterility testing applications.
• One-touch automated cleaning cycle flushes entire fluid path with air and rinse solution, minimizing cross-contamination between batches.

Sample Compatibility & Compliance

The GH-ZLR01 is validated for use with aqueous buffers, saline solutions, peptone water, tryptic soy broth, and other common microbiological diluents. Its gravimetric methodology inherently compensates for variations in liquid density, permitting reliable operation with ethanol-containing media or glycerol-stabilized suspensions. The device conforms to mechanical safety standards IEC 61010-1 and electromagnetic compatibility per IEC 61326-1. While not a standalone regulated device under FDA 21 CFR Part 11, its touchscreen interface supports audit trail-enabling firmware (via optional external logging server), facilitating alignment with GLP and GMP documentation requirements. All wetted materials comply with USP Class VI biocompatibility specifications.

Software & Data Management

The embedded HMI runs a deterministic real-time OS with non-volatile parameter storage. Users define dilution schemes—including target concentration, diluent type, and final volume—via intuitive touch interface; the system auto-calculates required stock volume and diluent mass in real time. All dispense events are timestamped and logged locally with mass delta, pump runtime, and error flags. Export options include CSV via USB port for integration into LIMS or ELN platforms. Optional firmware upgrade enables configurable user roles (Operator, Supervisor, Admin) and electronic signature capture for critical protocol execution—supporting ALCOA+ data integrity principles.

Applications

• Microbial enumeration (ISO 4833-1, ISO 6887-1): Accurate preparation of 10-fold serial dilutions from primary enrichment broths.
• Food and beverage quality control: Standardized dilution of homogenized samples into stomacher bags for subsequent plating or MPN analysis.
• Pharmaceutical environmental monitoring: Reproducible dilution of settle plate rinsates or swab extracts prior to membrane filtration.
• Clinical microbiology labs: Preparation of calibrated inocula for AST (antibiotic susceptibility testing) per CLSI M07 guidelines.
• Reference material dilution: Traceable preparation of certified reference standards for method validation studies.

FAQ

Does the GH-ZLR01 require calibration before each use?

No—factory calibration is retained in non-volatile memory. Daily verification using certified test weights (500 g and 2000 g) is recommended per ISO/IEC 17025 internal quality control protocols.
Can the instrument handle viscous samples like milk or soil suspensions?

Yes—the gravimetric control loop adapts to flow resistance changes; however, optimal performance requires selection of appropriate tubing ID (e.g., 3.2 mm inner diameter) and reduced pump speed for viscosities >100 mPa·s.
Is the touchscreen interface compatible with glove use in biosafety cabinets?

Yes—the projected capacitive display supports operation with nitrile and latex gloves without loss of responsiveness.
What maintenance intervals are recommended?

Peristaltic pump tubing should be replaced every 500 hours of cumulative operation or after 200 autoclave cycles; load cell zero-point verification is advised weekly.
Does the GH-ZLR01 support network connectivity or remote monitoring?

Standard configuration includes USB host port only. Ethernet or Wi-Fi modules are available as factory-installed options for centralized lab equipment management systems.