| 摘要 |
<p>A device for detecting air in large bore thin walled transparent tubing 14 comprises a body 12 providing accommodation for the tubing; an LED 21 in a passage 19 in body 12 for transmitting light energy towards the tubing 14; a phototransistor 20 mounted in an orthogonally extending passage 18 for receiving light transmitted by LED 21 and modified by changes in the constituency of fluid passing through tubing 14, and an optical spacer in the form of a slotted collar 15 of material optically matched to the material of tubing 14 occuping space between LED 21 and the tubing 14 and phototransistor 20. <IMAGE></p> |
