Dual sensor air-in-line detector
First Claim
1. In a device for detecting and indicating the presence of gas in liquid conducting tubing, the device comprising a member defining a passage for accommodating tubing;
- a transmitter for transmitting radiation towards said passage; and
a receiver for receiving from said passage radiation which has passed through said tubing, the receiver being operable to produce an output signal when gas is present in the tubing,the improvement comprising means for eliminating false detections made by said receiver that gas is present in the tubing length and comprising;
(i) a second receiver for receiving from said passage, radiation which has passed through said tubing, the second receiver being operable to produce an output signal when gas is present in the tubing, the second receiver making false detections under different liquid conditions from the first receiver, and(ii) Processing means operatively connected to both receivers to receive said output signals to provide an indication that gas is present in the tubing only when the output signals from both receivers are present; and
(iii) an optical spacer defining said passage and occupying space between said passage and said transmitter and between said passage and said receivers, the optical spacer comprising a cylindrical element having a dielectric constant greater than that of air, said tubing passage extending along a longitudinal axis of the cylindrical element for accommodating said tubing in intimate contact with said cylindrical element; and
(iv) said transmitter and said first and second receivers are operative in the infrared spectrum.
1 Assignment
0 Petitions
Accused Products
Abstract
A device for the reliable detection of air or air bubbles in transparent or translucent tubing carrying a fluid which includes a transmitter element for transmitting a light beam to the fluid contained in a large-bore thin-walled transparent tubing, and a pair of first and second light receiver devices for receiving reflected and transmitted light emitted from the transmitter element and which is incident upon the fluid conducting tubing. The light transmitter and receivers are located within a body member around the fluid conducting tubing. Also, an acrylic optical spacer which has a passage for accommodating the tubing is located within the body member. One light receiver is disposed at a 90° angle in relation to the optical axis of the transmitter, while the other receiver is arranged at a 180° angle. Outputs of the light receivers are applied to a processor, which processes the light receivers outputs to detect air in the tubing.
78 Citations
15 Claims
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1. In a device for detecting and indicating the presence of gas in liquid conducting tubing, the device comprising a member defining a passage for accommodating tubing;
- a transmitter for transmitting radiation towards said passage; and
a receiver for receiving from said passage radiation which has passed through said tubing, the receiver being operable to produce an output signal when gas is present in the tubing,the improvement comprising means for eliminating false detections made by said receiver that gas is present in the tubing length and comprising; (i) a second receiver for receiving from said passage, radiation which has passed through said tubing, the second receiver being operable to produce an output signal when gas is present in the tubing, the second receiver making false detections under different liquid conditions from the first receiver, and (ii) Processing means operatively connected to both receivers to receive said output signals to provide an indication that gas is present in the tubing only when the output signals from both receivers are present; and (iii) an optical spacer defining said passage and occupying space between said passage and said transmitter and between said passage and said receivers, the optical spacer comprising a cylindrical element having a dielectric constant greater than that of air, said tubing passage extending along a longitudinal axis of the cylindrical element for accommodating said tubing in intimate contact with said cylindrical element; and (iv) said transmitter and said first and second receivers are operative in the infrared spectrum. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- a transmitter for transmitting radiation towards said passage; and
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8. A device for detecting and indicating the presence of gas in liquid conducting tubing, the device comprising
a member defining a passage for accommodating tubing; -
a transmitter for transmitting radiation towards said passage; a first receiver for receiving from said passage radiation which has passed through said tubing, the first receiver being operable to produce an output signal when gas is present in the tubing and making false detections that gas is present in the tubing under first liquid conditions a second receiver for receiving from said passage radiation which has passed through said tubing, the second receiver being operable to produce an output signal when gas is present in the tubing and making false detections under different liquid conditions from the first liquid conditions; processing means operatively connected to both receivers to receive said output signals to provide an indication that gas is present in the tubing only when the output signals from both receivers are present and an optical spacer defining said passage and occupying space between said passage and said transmitter, and between said passage and said receivers, the optical spacer comprising a cylindrical element having a dielectric constant greater than that of air, said tubing passage extending along a longitudinal axis of the cylindrical element for accommodating said tubing in intimate contact with said cylindrical element. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A device for detecting and indicating the presence of air in liquid conducting tubing, the device comprising:
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a member defining a passage for accommodating tubing; a transmitter for transmitting light towards said passage; a receiver for receiving from said passage light which has passed through said tubing, the receiver being operable to produce an output signal when (a) air is present in the tubing and/or (b) when the dilution ratio of the liquid in the tubing is below a first predetermined threshold; a second receiver for receiving from said passage light which has passed through said tubing, the second receiver being operable to produce an output signal when (c) air is present in the tubing and/or (d) when the dilution ratio of the liquid in the tubing is above a second predetermined threshold; and processing means operatively connected to both receivers to receive said output signals to provide an indication that air is present in the tubing only when the output signals from both receivers are present; and an optical spacer defining said passage and occupying space between said passage and said transmitter, and between said passage and said receivers, the optical spacer comprising a cylindrical element having a dielectric constant greater than that of air, said tubing passage extending along a longitudinal axis of the cylindrical element from accommodating said tubing in intimate contact with said cylindrical element.
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Specification