Proportionnal pressure controller QB from PROPORTION AIR
The QB series valve uses Proportion- Air closed loop technology for Pressure control. It gives an output pressure proportional to an electrical command signal input.
The QB1 is a complete closed loop servo system consisting of valves, manifold, housing and electronic controls. Pressure is controlled by the use of two solenoid valves. One valve functions as inlet control, the other as exhaust. The pressure output is measured by a pressure transducer internal to the QB1 and provides a feedback signal to the electronic controls. This feedback signal is compared with the command signal input. A difference between the two signals causes one of the solenoid valves to open, allowing flow in or out of the system. Accurate pressure is maintained by controlling these two valves.
The QB2 is similar to the QB1 but uses a double loop control scheme. In addition to the internal pressure transducer, the QB2 receives an electrical signal from an external sensing device. This primary feedback signal is compared against the command signal input. This comparison is then summed with the internal pressure transducer signal. The gain of the circuit is such that priority is given to the external feedback signal. A difference between the command signal and the feedback signal causes one of the solenoid valves to be activated.
A monitor output is provided for the system measurement. All QB valves come standard with an analog voltage monitor output.
QB1 monitor output is an amplified signal from the internal pressure transducer. QB2 monitor output is a buffered signal from the primary external transducer connected to the QB2.
For QB valves with model number TFEE or TFIE the monitor output is voltage. The monitor output is analog current, if the valve model number is TFEC or TFIC. See ordering information for further details.
Accuracy: +/- 0.2% full scaleRepeatability :+/- 0.02% full scaleHysteresis: +/- 0.15% full scaleService temperature: 0-70°CFlow rate: few milliliters to 3600 Nm3/hPressure : from vacuum to +70 bar G15-24VDC; 250mA maxCommand signal : 0-10VDC or 4-20mAProtection rating : NEMA 1Filtration 40 Micron (included)