Description
The ROXY-4 universal controller is a versatile, four-channel, O2 and general purpose gas controller. It can regulate many variables such as oxygen, CO2, water vapor, or pressure by using the analog output of an external analyzer or fuel cell. Four independent channels give the flexibility to control four separate chambers or multiple variables in fewer chambers.
For example, consider controlling the oxygen concentration within four glove boxes at 10%, 25%, 35% and 50% O2. An oxygen sensor in each glove box sends information to the ROXY-4. If the setpoint for that glove box is hypoxic, nitrogen is pulsed into the glove box to bring the O2 down to the setpoint. If the setpoint is hyperoxic, it will pulse oxygen into the glove box until the setpoint is reached. In either case, after the initial setpoint is established, almost no gas is used unless a disturbance occurs. When a disturbance is detected, gas is added in pulses just until the setpoint is recovered. The result is smooth and efficient control with minimal gas use.
The setpoint control algorithm can create stable or profiled environments for cell cultures, material testing, hypoxia, hyperoxia and many other applications. In addition to its standalone mode, the ROXY-4 can be computer-controlled over a serial link. The communications protocol is open source and fully documented in the user manual.
Oxygen levels tracked over approximately 70 minutes in a system regulated by a ROXY gas controller. The ROXY system shows tight adherence to the oxygen level set point with extremely low variability.