Abstract: A hand tool is provided for securing adjacent vinyl siding strips. First and second handles, bearing first and second jaws, are pivotally attached. A first jaw forms a channel, and the second jaw supports a crimp bolt. A portion of one siding strip is disposed between the jaws. Actuation of the jaws moving the crimp bolt against the vinyl strip pushes the strip into the channel forming crimps on the strip, which crimps facilitate formation of a positive lock with an adjacent strip.

Abstract: A respiratory CO.sub.2 detector (10) comprising an infrared lamp source (44) and an infrared detector (50) responsive thereto forming an optical path for detecting the change in CO.sub.2 concentration, or an obstruction in a cuvette (42). The output of the infrared detector (50) provides a high and low voltage signal to be applied to a feedback control loop (12) and to an output circuit (14).The feedback control loop (12) includes a peak detector (22), a contamination detector (24), a pulse-width modulator (26) and a low pass filter (28), the latter providing a DC bias on the infrared lamp (44). The peak detector (22) is connected to the pulse-width modulator (26) to maintain the lamp voltage constant and is connected to comparators (56,62) to compare both outputs of the peak and contamination detectors (22,24). The contamination detector (24) will respond to blockage in the cuvette (42).