Building the linear peristaltic air pump for
            performing vacuum experiments.


 Start out with the stick, hose and the tape.

 The stick should be about a yard or meter in length. The hose should be about 2 to 2 1/2 feet long.
 The surfaces of the hose and the stick should be clean so that the tape will adhere to them.
 Wipe the hose with an acetone moistened paper towel to remove any excessive wax or powder.
 Remove loose traces of saw dust from the stick by sticking tape and then stripping it off again.
Toss this tape away.

   Attach one end of the hose to the stick 
with a two inch length of tape.
 ( Sticks used for wet service pumps should
be completely covered with the duct or gaffer's tape to keep the wood dry. )
Next tie the other end of the hose to the stick.
  Lay the hose along the stick. Secure the 
other end like you first did with the first 
end. Grasp both ends of the hose and it a 
mild stretch to ensure that it lies straight.
 Covering the hose between the first and second bands of tape.
 This creates the unique restraining feature that keeps the hose from squirming out from under
the rollers.   You can either cover the hose and the stick by laying the tape along the length or with a
helical path around.
 Cover the portion of the stick between the
two bands that hold down the hose.
 Adding the check valve.
 Although the colored rubber vegetable bands will work for a short time, those made from discarded bicycle tire tubes have far greater endurance of being run over by the brayers.
  Attach an inflated balloon to the other or 
the inlet end of the pump hose. 
 Attach a smaller hose to the exhaust end of the pump and run the other end to a clear
water filled glass cup.
 Look for bubbles comming out of the
submerged end of the hose. 
 Adjust the pressure of this valve by adding
or removing bands or wraps  to "tune" it
just on the stopped side of threshold.

  Operating the linear peristaltic air pump.
 Tape the experiment end of the stick down to the far edge of the table from where you are
standing or sitting.
 After connecting an experiment or a gage to the end of the pump, take a brayer in each hand.
 Place a brayer close to the experiment end of the hose, press down firmly and draw the brayer
towards your the check valve end of the hose. Before running the first, place the second brayer in the starting position  and do the same while you complete rolling the first brayer over the check valve
 The original linear peristaltic pump devised 
by Nyle Steiner did not have a check valve.
 You had to be careful not to lift one 
brayer before applying the other. Doing so 
would allow the air that was removed to
immediately rush back into the experiment. 
 This new design is forgiving to less than perfect operation. 
 The check valve prevents the air from returning into the pump and the attached 
experiment when both brayers are lifted off the 
  Be sure that you run the brayer firmly over 
the valve to squeeze out the remaing air.

  Another view of my setup.
 Expect more changes to these pages as I 
get more pictures, information and maybe 
a movie of the pump operation. 
 So far this page work has been mostly a 
solo effort.

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