Many devices have been developed to Measure Pressure and vacuum. Instruments used for Measuring Pressure are called pressure gauges or vacuum gauges. These gauges can measure pressures of many types of substances, including liquids, gases and fluids, but cannot measure pressure between two solid surfaces. Other techniques are needed for Measuring Pressure between two solid surfaces that contact each other.
Pressure indicating sensor film, such as Fujifilm Prescale®, is the preferred method to Measure Pressure between any two contacting, mating, or impacting surfaces. Fujifilm Prescale® is a Mylar®-based film that contains a layer of tiny microcapsules. The application of force upon the film causes the microcapsules to rupture, producing an instantaneous and permanent high resolution topographical image of pressure variation across the contact area. Figure 1 demonstrates how Fujifilm Prescale® is used for Measuring Pressure on a solar array junction box before it is mounted on the array.
|Step 1: For Measuring Pressure prior to applying adhesive, cut and position a piece of Fujifilm Prescale® film on the bottom of the solar array junction box and apply force.||Step 2: Instantaneously and permanently, the film captures both the pressure distribution and magnitude that occurs between the contacting surfaces.
||Step 3: A Topaq® analysis may be performed on the Prescale® image. This provides a pseudo-color pressure map. The Topaq® software can also generate a pressure profile graph as shown.|
The solar array junction box has a fixed mount; therefore, it does not move. In some instances, however, one must Measure Pressure for dynamic events.
Driver pedal motions are dynamic events. Neil Dixon of Jaguar LandRover and Sam Brook, Rob Freeman, George Rosala, and Felician Campean of the University of Bradford in the UK were studying driver pedal motions and reported on their work in a paper titled, “Ergonomic Data Measuring System for Driver-Pedals Interaction.”
To Measure Pressures, the authors used a customized pressure pad system that was developed by Sensor Products Inc. This system was based on Tactilus® piezoresistive array technology for Measuring Pressures between the driver and the vehicle. Table 1 shows the details of the pressure arrays used for this work. These arrays were linked to a laptop computer containing Tactilus® software.
Figure2 gives a representative example of a Tactilus® pressure profile between the driver and the vehicle. The seat pad is at left in the figure. The floor pad is in the middle, and the accelerator pedal pad is on the right. The areas in red correspond to the highest pressures.
Fig 2: Representative Tactilus® Pressure Profile Data between Driver and Vehicle