A drip chamber is a device used to allow gas (such as air) to rise out from a fluid so that it is not passed downstream. It is commonly employed in delivery systems of intravenous therapy and acts to prevent air embolism.
The use of a drip chamber also allows an estimate of the rate at which fluid is administered. For a fluid of a given viscosity, drips from a hole of known size will be of nearly identical volume, and the number of drips in a minute can be counted to gauge the rate of flow. In this instance the rate of flow is usually controlled by a clamp on the infusion tubing; this affects the resistance to flow. However, other sources of resistance (such as whether the vein is kinked or compressed by the patient's position) cannot be so directly controlled and a change in position may change the rate of flow leading to inadvertently rapid or slow infusion. Where this might be problematic an infusion pump can be used which gives a more accurate measurement of flow rate