A method of creating a permanent record of Force-time or Load-time using inexpensive pressure sensitive strips. These strips change color with applied pressure, the color being equivalent to the pressure applied.The strips are commercially available. The mechanism proposed increases the utility by giving a time resolved history of the load or force or pressure applied.
The narrow strip passes beneath the pressure roller and is transported by a feed mechanism such as rollers or a gravity method.As the pressure is applied it is recorded via color change on the strip. The actual force levels are determined by visual comparison with a calibrated chart or in a more sophisticated approach by a colorimeter.
The device is useful for recording the output of impulse cartridges, attitude control motors, and forces and loads on various parts of an aircraft or spacecraft.
It may find utility in the commercial arena also.