Hamilton ARC Dissolved CO₂ Probes

CO₂NTROL Description

Hamilton CO₂NTROL is a solid-state, in-line dissolved CO₂ sensor that lets you treat CO₂ like any other live process variable instead of a periodic lab check. It measures dissolved carbon dioxide (DCO₂) directly in the bioreactor in real time, over a working range designed for bioproduction (5 to 1000 mbar, corresponding to up to ~1500 mg/L in the liquid phase at standard conditions). This allows active control of sparging, stripping, and feed strategy to protect cell health, stabilize metabolism, and improve titer and batch-to-batch consistency across scale-up.

Traditional Severinghaus-style CO₂ probes infer CO₂ indirectly using an internal pH measurement and an electrolyte reservoir, leading to drift, liquid handling, and frequent recalibration. CO₂NTROL instead uses a solid-state mid-IR / NDIR optical measurement: CO₂ crosses a gas-permeable interface and the sensor reads CO₂-selective infrared absorption directly, with built-in temperature compensation. This design eliminates refillable electrolyte and consumable internals, so there’s no CO₂ consumption, no ammonia fouling, and minimal ongoing maintenance beyond simple recertification in air or certified gas. Calibration is done in air and gas standards instead of elaborate multi-point wet calibration.

Because CO₂NTROL is part of Hamilton’s Arc family, the transmitter lives inside the probe. It communicates via RS-485 Modbus RTU and stores its own calibration, health, and diagnostic data onboard, so Daisy Process can pull live DCO₂ and temperature without an external transmitter.

Mechanically, CO₂NTROL RS485 is built for upstream bioprocess. It’s a hygienic, EHEDG-approved design (EL Class I with Hamilton’s sanitary socket) using 1.4435 stainless steel wetted metal surfaces polished to Ra < 0.4 µm, plus EPDM and FDA-listed silicone elastomers. It mounts like a standard PG13.5 process probe and is offered in common insertion depths (a-lengths) such as 120, 160, 225, 325, and 425 mm, making it suitable for R&D glass reactors, pilot skids, and production stainless vessels. The sensor is autoclave, SIP, and CIP compatible, steam sterilizable up to ~140 °C, and operates at pressures roughly −1 to 12 bar.

In short: CO₂NTROL makes inline DCO₂ a first-class control parameter, not an offline assay.

Technical Specs (Typical CO₂NTROL RS485)

• Measurement principle: Solid-state optical / mid-IR (NDIR) absorption of CO₂-selective wavelengths with temperature compensation; no electrolyte required and no CO₂ consumed.
• Process value: Dissolved CO₂ reported directly; configurable readout units include mbar, mmHg, hPa, %vol, %sat, and mg/L / ppm equivalents, plus built-in temperature (NTC 22 kΩ).
• Range / accuracy: ~5–1000 mbar (~0.5–100 %vol or ~7.5–1500 mg/L at 25 °C, 1 atm); accuracy at 25 °C is ±5 mbar from 5–100 mbar and ±5% above 100 mbar.
• Digital interface: RS-485 Modbus RTU (Arc); Daisy Process reads this natively as a digital sensor.
• Form factor: PG13.5 process connection; available a-lengths such as 120 / 160 / 225 / 325 / 425 mm to match typical bioreactor ports from lab to production.
• Hygiene & compliance: EHEDG EL Class I hygienic design, stainless steel 1.4435 with Ra < 0.4 µm, EPDM and silicone meeting FDA 21 CFR 177.2600, ready for GMP documentation.
• Sterilization & conditions: Autoclave / SIP / CIP capable; steam sterilizable to ~140 °C; specified operating temp −10 to 140 °C (CO₂ reading available up to ~60 °C); pressure window roughly −1 to 12 bar.

Frequently asked questions

What is the Hamilton CO2NTROL Arc probe?

It is a solid-state, inline dissolved CO2 probe from the Hamilton Arc family. The transmitter sits inside the probe, which reports dissolved CO2 and temperature over RS-485 Modbus RTU and stores its own calibration and diagnostics.

Does it work with the Daisy Process?

Yes. Connect it to one of the four ports on the Daisy Process with an ARC VP8 cable, and the Daisy Process reads dissolved CO2 and temperature without an external transmitter. Live values appear in the Daisy Controller Software.

How is it different from a Severinghaus-style CO2 probe?

Severinghaus-style probes infer CO2 indirectly from an internal pH measurement and an electrolyte reservoir. CO2NTROL measures CO2 directly with solid-state NDIR optics, so there is no electrolyte to refill and no CO2 is consumed.

What measurement range does it cover?

The range is 5 to 1000 mbar of dissolved CO2, designed for bioproduction. Calibration is done in air and gas standards.

Can it be sterilized, and which lengths are available?

It is autoclave, SIP and CIP compatible, and steam sterilizable up to about 140 °C. Lengths are 120, 160, 225, 325 and 425 mm with a PG13.5 connection.