HACH CA9400 Single-Channel / Dual-Channel Transmitter

Overview

The HACH CA9400 Single-Channel / Dual-Channel Transmitter is an industrial-grade process transmitter engineered specifically for bioprocess monitoring in fermentation applications. It operates on analog signal conditioning principles, accepting standard 4–20 mA or mV-level inputs from potentiometric pH electrodes and galvanic or polarographic dissolved oxygen (DO) sensors. The device implements precision analog-to-digital conversion with temperature-compensated signal processing to ensure stable, drift-resistant measurements under dynamic bioreactor conditions. Designed for integration into sterile, controlled microbial cultivation environments—including stainless-steel fermenters, single-use bioreactors, and pilot-scale upstream processes—the CA9400 delivers continuous real-time data acquisition without requiring external signal conditioning modules. Its architecture supports both standalone operation and seamless connectivity to distributed control systems (DCS) or programmable logic controllers (PLC) via industry-standard analog output loops.

Key Features

• Configurable single- or dual-channel operation: supports independent pH and/or DO measurement channels with channel-specific calibration, alarm thresholds, and output scaling
• High-resolution resistive touchscreen interface (800 × 480 pixels) with intuitive icon-driven navigation optimized for gloved-hand operation in cleanroom and biosafety level (BSL)-2 environments
• Integrated temperature compensation using Pt100 or thermistor inputs—automatically applied to pH and DO readings per NIST-traceable algorithms
• Dual 4–20 mA isolated analog outputs with HART® 7 protocol support for bidirectional configuration and diagnostics over the same wiring
• Programmable relay outputs (SPDT, 250 VAC/3 A) for local alarm activation, pump interlock, or gas dosing control based on user-defined setpoints and hysteresis
• IP66-rated polycarbonate housing with front-panel gasket and corrosion-resistant mounting hardware suitable for humid, chemically aggressive bioprocessing areas
• Non-volatile memory retains calibration history, event logs, and configuration parameters across power cycles—enabling full audit trail compliance

Sample Compatibility & Compliance

The CA9400 is compatible with all HACH-compatible analog pH electrodes (e.g., CPS11D, PHC101) and DO sensors (e.g., LDO101, DOA110), as well as third-party analog sensors meeting IEC 61298-1 output specifications. It complies with electromagnetic compatibility standards IEC 61326-1 (industrial environment) and functional safety requirements per IEC 61508 SIL 2 for basic alarm functions. While not certified for intrinsic safety, it may be deployed in Zone 2 classified areas when installed with appropriate barriers. The device supports GLP/GMP-aligned operation through configurable user access levels (Operator, Technician, Administrator), password-protected calibration locks, and timestamped calibration records exportable via USB. Firmware updates are performed offline to maintain system integrity during validation.

Software & Data Management

Configuration and diagnostics are managed locally via the embedded touch interface or remotely using HACH’s PC-based Instrument Manager software (v4.2+), which provides firmware update capability, batch export of calibration reports, and trend visualization of up to 30 days of historical data stored onboard. All configuration changes and calibration events are logged with ISO 8601 timestamps and operator ID tags. The transmitter supports optional Modbus RTU over RS-485 for integration into SCADA systems, enabling centralized data aggregation without additional gateway hardware. Audit trail records meet FDA 21 CFR Part 11 requirements for electronic records and signatures when used with validated instrument management workflows.

Applications

• Real-time pH and DO monitoring in microbial fermentation (E. coli, yeast, CHO cell cultures)
• In-situ control of acid/base and air/oxygen sparging in stainless-steel and single-use bioreactors
• Batch and fed-batch process validation per ICH Q5 and Q7 guidelines
• Environmental monitoring of wastewater treatment bioreactors and anaerobic digesters
• Quality control of media preparation and sterilization validation cycles
• Academic and contract development organization (CDO) bioprocess research requiring traceable sensor interfacing

FAQ

Can the CA9400 accept digital sensors such as ISM or Smart Electrodes?
No—the CA9400 is designed exclusively for analog sensor inputs (mV or 4–20 mA). Digital sensor protocols like HACH’s IntelliCAL™ or ISM require the HA series or SC1000 platform.
Is the device suitable for use in steam-in-place (SIP) or clean-in-place (CIP) environments?
The CA9400 itself is not SIP/CIP-rated; however, its remote mounting configuration (up to 30 m cable length) allows placement outside autoclavable zones while maintaining signal integrity via shielded twisted-pair cabling.
Does the CA9400 support automatic calibration verification (ACV)?
It does not perform ACV autonomously, but it stores calibration verification results manually entered by operators and flags deviations exceeding user-defined tolerance bands.
What is the maximum recommended cable length between the transmitter and analog electrodes?
For optimal noise immunity and signal fidelity, HACH recommends ≤15 m for pH electrodes and ≤30 m for DO sensors using twisted-shielded cable compliant with IEC 60794-2.