Figure 1:  The respirometer is composed of a 125 mL Erlenmeyer flask.  The stopper must fit tightly into the flask and the pipette must be securely attached with silicon cement.  The respirometer must be airtight except for the open end of the pipette.
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      Figure 2:  The graduated pipette must be inserted through the single-hole #4 stopper.  The silicon glue is attached to both sides of the pipette, sealing the pipette.  After the glue dries, the pipette-stopper combination may be tested for air tightness by placing the entire respirometer is a water bath.
       
       
       
       
       
       
       
       
       
       
       
       
       

      Figure 3:  The complete lab set-up showing the complete respirometer with germinating seeds.  Note the layers of absorbent and non-absorbent cotton in the bottom of the flask respirometer.  The germinating beans were placed on top of the non-absorbent cotton to keep them from being damaged by the 15% KOH.  The bio-gas pressure probe was attached to the tip of the pipette and the CBL.  The CBL was linked to a TI-93 graphing calculator for data collection.