Essential tremor. Essential tremor (ET, also referred to as benign tremor, familial tremor, or idiopathic tremor) is the most common movement disorder; its cause is unknown. It typically involves a tremor of the arms, hands or fingers but sometimes involving the head, vocal cords or other body parts during voluntary movements such as eating and writing.
Volumetric Pipettes Volumetric pipettes labeled TD (to deliver) at the upper end are designed to deliver the volume stated on the pipette. There will always be a small amount of liquid inside the tip after pipetting. If this liquid is blown out you will have delivered slightly more than the designed capacity of the pipette. Almost all of our pipettes are TD pipettes. However, other types do exist: Pipettes labeled TC (to contain) are designed to contain the volume stated on the pipette. Therefore, all liquid on a TC pipette should be expelled to obtain the desired volume.
Each thread size has a defined number of threads per inch (TPI). The 3/4 NPT pipe thread has 14 threads per inch. Both the TPI (threads per inch) and OD (outside diameter) of the thread are required for positive identification of thread size because several sizes have the same TPI. View our Pipe Fittings and Nipples Index Page.