Cooper Instruments & Systems ELF 4200 Flexiforce Paper Thin Sensor - Manual (Page 16)

CF10 13 6/24/08 Rev. H
4.0 OVERVIEW
This section outlines the Various Hardware and Software components that ship with your system.
4.1 Sensors
The sensor is an ultra-thin and flexible printed circuit. Sensors are available in three full-scale force ranges: Low
(25 lbf ), Medium (150 lbf ), and High (1000 lbf ). The "active sensing area" is a 0.375. diameter circle at the end of
the sensor. The sensors are constructed of two layers of substrate, such as a polyester film. On each layer, a
conductive material (silver) is applied, followed by a layer of pressure-sensitive ink. Adhesive is then used to
laminate the two layers of substrate together to form the sensor. The "active sensing area" is defined by the silver
circle on top of the pressure sensitive ink. Silver extends from the sensing area to the connectors at the other end
of the sensor, forming the conductive leads.
The sensor acts as a variable resistor in an electrical circuit. When the sensor is unloaded, its resistance is very
high (greater than 5 Meg-ohm); when a force is applied to the sensor, the resistance decreases. This resistance is
read, and an 8-bit analog-to-digital converter changes the output to a digital value in the range of 0 to 255.
There are three types of sensors available, as shown below:
4.2 Sensor Handle
The sensor’s tab is placed into the sensor handle. The handle gathers data from the sensor, processes it, and
sends it to your computer through USB connection
Note: our previous systems shipped with Serial handles. It is not recommended to use both the serial ELF and the
USB ELF handles simultaneously.
4.3 Screen Display
4.3.1 Screen Display
This section is a comprehensive look at the ELF screen display. Each component of the display, as well as each
Main Menu option, will be described in detail.