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When working with pump tubing of small size (#13, #14, Orange-Yellow, and Yellow-Blue), it is necessary to use microbore tubing to hydraulically connect the pump to the experimental apparatus. The microbore tubing most commonly used in the lab is PTFE with OD of 1.6 mm (1/16") and ID of 0.8 mm (1/32"). This tubing can be purchased at Cole-Parmer. To connect the microbore tubing to the peristaltic pump tubing requires a barbed tube fitting sized for tubing of 1/16" ID (can be purchased at McMaster-Carr), shown below.
(Note: The fitting depicted below In the following steps, a small semi-clear fitting is shown to illustrate the process. This type of fitting can split after undergoing the procedure shown below, so larger 1/16" fittings, like the one shown above, are recommended.)
This barbed tube fitting inserts easily into the small diameter pump tubing as shown below.
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The same process of stretching the microbore tubing to fit it snugly into the barbed fitting can be used for other applications. One common application is to bore a 1/16" hole in a 1/4" push-to-connect plug so that the plug can then be inserted into a push-to-connect through-wall or tee fitting. This is the most common way to make the connection between microbore tubing and an experimental apparatus. The process for drilling holes in 1/4" plugs is as follows.
The first step in drilling a hole through a 1/4" plug is to hollow it out as shown below (apologies for the orientation, this is a problem with Confluence). The drill bit used in this photograph is 1/8". Any size smaller than the shaft of the plug and larger than 1/16" (the OD of the microbore tubing) will work. To drill this hole, it is important that the plug be fixed in a vertical position, which is what the drill vise is used for in this image. Also note in the foreground that there is a clamp holding the drill vise in place. This is to keep the drill bit centered on the vertical axis of the plug. The red tape on the drill bit is there to mark at what point the drilling should stop. If you drill straight through the plug with the large bit, you have rendered it useless. A good target to aim for is to drill to within 1/16" of the bottom of the plug and stop. That way, you won't have to thread the microbore tubing very far.
Once you've hollowed out the plug, the next step is to drill the small hole through which the microbore tubing will fit. The procedure is simply to drill with the smaller bit in the center of the bottom of the plug. If you hollowed out the plug correctly, you should not have to drill very far before you've cleared the material at the bottom of the plug.
Again, there is freedom in the choice of drill bit. The key constraint is that the hole provide an interference fit (i.e., it must be smaller than 1/16", the OD of the microbore). The other constraint is that it is not desirable to have a hole so small that it is nearly impossible to thread the microbore tubing through it. As you will have noticed if you performed the above steps for threading the microbore through a barb, it is actually a considerable challenge to fit the 1/16" tubing into the 0.047" hole in the barb. For this reason, a 0.052" (#55 wire gauge) drill bit was chosen so as to be tight-fitting, but not too difficult to thread through. These bits can be found in the drill drawer of the tool chest.
Pump Calibration
ProCoDA has a pump calibration routine available on the configuration tab. The pump must be on and running (controlled by ProCoDA) in order to complete the calibration.
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