Methods of calibrating a pH sensor fixed within an enclosed vessel are disclosed. The methods include introducing a buffer into the enclosed vessel, introducing a gas mixture comprising CO.sub.2 into the enclosed vessel, measuring a pH signal of the solution, measuring a CO.sub.2 concentration of a headspace gas of the solution, and calculating a pH value with a buffer calibration curve. The methods include calculating a calibration parameter with a sensor calibration curve and calibrating the pH sensor with the calibration parameter. Reactor systems are also disclosed. The systems include an enclosed reactor, a pH sensor, a CO.sub.2 sensor, a temperature control subsystem, and a controller. Methods of facilitating pH sensor calibration without sampling in a bioreactor system are also disclosed. The methods include providing a controller and providing instructions to operably connect the controller to the pH sensor and the CO.sub.2 sensor.

Methods of calibrating a pH sensor fixed within an enclosed vessel are disclosed. The methods include introducing a buffer into the enclosed vessel, introducing a gas mixture comprising CO.sub.2 into the enclosed vessel, measuring a pH signal of the solution, measuring a CO.sub.2 concentration of a headspace gas of the solution, and calculating a pH value with a buffer calibration curve. The methods include calculating a calibration parameter with a sensor calibration curve and calibrating the pH sensor with the calibration parameter. Reactor systems are also disclosed. The systems include an enclosed reactor, a pH sensor, a CO.sub.2 sensor, a temperature control subsystem, and a controller. Methods of facilitating pH sensor calibration without sampling in a bioreactor system are also disclosed. The methods include providing a controller and providing instructions to operably connect the controller to the pH sensor and the CO.sub.2 sensor.

A rain activated chemical applicator having: a means adapted to detect rainfall data and the means also being in communication with a controlling means; a controlling means; and a chemical dispensing means being in communication with the controlling means and wherein the chemical dispensing means comprises a manual priming pump to create a syphon, a valve, a flow meter and a discharge hose; the applicator is arranged such that when in use the applicator is connected to a storage means (e.g. a drum or tank) containing chemicals (e.g. flocculants and/or coagulation chemicals etc) and wherein when there is rainfall this is detected by the means adapted to detect rainfall date and the rainfall data is processed by the controlling means and the controlling means then determines the amount of chemicals that the chemical dispensing means should dispense into a body of water (e.g. a pond) and then the dispensing means dispenses these chemicals into the body of water. Sediment control is a significant environmental consideration when undertaking earthwork projects. The use of flocculants and/or coagulation chemicals is one way of controlling the sediment. Typically, these flocculants and coagulation chemicals are dispensed by chemical applicators. Known chemical applicators have high labour costs, are inaccurate and are prone to failure. The rain activated chemical applicator addresses this problem.

Chemical liquid is injected into a tank. A concentration of a first gas dissolved in the chemical liquid is detected. Based on the detected concentration of the first gas, at least one of the first gas and a second gas is injected into the tank to sustain at least one of the concentration of the first gas and a concentration of the second gas in a range of a target value.

A system and method provides a more precise mole delivery amount of a process gas, for each pulse of a pulse gas delivery, by measuring a concentration of the process gas and controlling the amount of gas mixture delivered in a pulse of gas flow based on the received concentration of the process gas. The control of mole delivery amount for each pulse can be achieved by adjusting flow setpoint, pulse duration, or both.

A method for controlling the saturation level of gas in a liquid discharge includes obtaining temperature and pressure measurements of a solvent in a mixing vessel and obtaining a pressure measurement of a source feedstock in a feedstock tank, correlating the temperature and pressure measurements of the solvent to baseline data to generate a theoretical uptake rate for the source feedstock into the solvent and a theoretical flow rate of the source feedstock into the mixing vessel, and determining a required opening setting for a feedstock valve in the feedstock input line in order to achieve a desired liquid displacement in the mixing vessel. The method includes determining an uptake duration and achieving an uptake displacement equivalent to the reverse of the desired liquid displacement. The method includes generating a valve operating control law for how the feedstock valve should function in a cycle.

A method for controlling the saturation level of gas in a liquid discharge includes obtaining temperature and pressure measurements of a solvent in a mixing vessel and obtaining a pressure measurement of a source feedstock in a feedstock tank, correlating the temperature and pressure measurements of the solvent to baseline data to generate a theoretical uptake rate for the source feedstock into the solvent and a theoretical flow rate of the source feedstock into the mixing vessel, and determining a required opening setting for a feedstock valve in the feedstock input line in order to achieve a desired liquid displacement in the mixing vessel. The method includes determining an uptake duration and achieving an uptake displacement equivalent to the reverse of the desired liquid displacement. The method includes generating a valve operating control law for how the feedstock valve should function in a cycle.

The device for adjusting the concentration of a gas in a liquid includes a cartridge in which the concentration of the gas in the liquid is adjusted, a pipe for supplying the liquid into the cartridge, a pipe for supplying gas into the cartridge, and a pipe for discharging the liquid from the cartridge. The gas supply pipe includes an expansion valve with of which the pressure setpoint that is controlled by a setpoint for the quantity amount of gas in the liquid and by an amount of a quantity of gas in the liquid measured by a gas concentration sensor located in the liquid discharge pipe.

The device for adjusting the concentration of a gas in a liquid includes a cartridge in which the concentration of the gas in the liquid is adjusted, a pipe for supplying the liquid into the cartridge, a pipe for supplying gas into the cartridge, and a pipe for discharging the liquid from the cartridge. The gas supply pipe includes an expansion valve with of which the pressure setpoint that is controlled by a setpoint for the quantity amount of gas in the liquid and by an amount of a quantity of gas in the liquid measured by a gas concentration sensor located in the liquid discharge pipe.

Systems, methods, and software program products for dispensing chemical solutions. A controller receives a signal from a pressure sensor indicative of a pressure of a diluent. The controller determines an expected flow rate of the diluent through an eductor based at least in part on the pressure of the diluent. The controller may further determine an expected concentration of a chemical product in the solution dispensed from a discharge port of the eductor. Based on the expected flow rated and concentration of the chemical product, the controller determines a duration of a dispense stage of a dispensing operation required to dispense a predetermined dose of the chemical product. The controller then causes the diluent to flow through the eductor for the determined duration of the dispense stage. A check valve on the output of the eductor prevents dissimilar chemicals from mixing and reduces a response time of the eductor.