Mechatronic Products Sensors Pressure distribution measurement system Super thin pressure sensor 6 DoF force/torque sensor   HOME > Products > Mechatronic Products and Sensors > Sensors > Super thin pressure sensor > FAQ About the FlexiForce Sensor What materials are used for the FlexiForce Sensor? Pressure sensitive ink is employed for the sensing area, while silver is used for the wiring part. They are coated with two-layered polyester films.   What is the resistance of the sensor? The resistance of the sensor is about 10 m under no-load, while it is 20 k ±30 % under the maximum-load. What is the sensor life? It depends on usage. If the sensor is not exposed to severe conditions such as measurement of load by a sharp edge or shear force, the sensor can be used repeatedly. The sensor withstands a million loading cycles at the force of around 25 kg (50 lbs), (according the company's test conditions). Can I measure tensile strength or shear force? We do not recommend using the sensor for measurement of tensile strength or shear force, because the sensor is designed to measure force applied perpendicularly to the sensor surface. If you use the sensor for such measurements, the sensor life will be shortened and repeatability of measurements will be decay. Can you provide a sensor sample? Sorry, but we do not provide samples as a rule. Is the sensor attachable to a measurement surface? If you need to attach the sensor to the measurement surface, please use tape, if possible. If you use glue, you must confirm that the glue will not deteriorate the sensor surface (polyester) before use. In addition, you should not use glue on the pressure sensitive surface. If it is absolutely necessary to use glue, please apply the glue as evenly as possible. If the glue is unevenly applied, the load might be unevenly applied to the test subject during measurement. This may result in incorrect measurement data. What is the tolerable range of drive voltage energized to the sensor? The standard tolerance is 0.1 V to 18 V (the necessary signal-to-noise (S/N) ratio is obtained). Note that some reported that, where the sensor was energized at high voltage and was exposed to a certain load, output values decreased slowly. Thus, it is ideal to use the sensor within an energizing voltage range from 0.1 V to 7 V. In addition, please use constant voltage for the driving voltage. (Avoid using voltage dividers.) About ELF system What is the maximum data acquisition speed of the ELF system? The maximum data acquisition speed of the standard ELF system is 200 Hz. For the High-speed ELF system, the speed is 5760 Hz.   *The data acquisition speed is expressed by "Hz", which means the frequency of reading sensor outputs per second. What is the resolution of the ELF system? An analog-to-digital (A/D) converter of 8 bits (256 gradation sequences) is employed for the sensor handle of the ELF system, where loads applied to the sensor are converted into digital values within the range of zero to 255. Then, the sensor outputs these digitalized data. About break-in-operation and calibration Why is break-in-operation necessary for the sensor? It is necessary for the sensor to gradually adjust to pressure before calibration and measurement for accurate pressure measurement. The break-in-operation is effective to curb influence from drift or hysteresis. The break-in-operation is effective for new sensors or those that have not been used for some time. To allow the sensor to adjust to pressure, the sensor is subjected to four or five loading cycles, where a load equivalent to 110 % of the capacity is applied to the sensor until the sensor stabilizes, and then is removed. The contact surface where the pressure is placed must be the same portion to be used in the calibration or actual measurement. Why is calibration necessary for the sensor? Calibration is a method to convert electrical outputs from the sensor to data expressed in an engineering unit such as a gram or Newton. Differences in sensitivity among sensors are corrected through the calibration. In addition, the calibration improves repeatability and curbs influence from drift. What is the time interval between break-in-operations of the sensor? Break-in-operation must be performed once every two or three weeks. Apparently, more frequent break-in-operation will increase the accuracy of pressure measurement. About operation environments Is it submersible? The sensor is not waterproof. Please do not use it in water or in any place where the sensor is exposed to water. Does use in a very humid environment influence the sensor? The sensor has gone through high-humidity environmental testing. As result, we have confirmed that the sensor is properly operational in such an environment. Do magnetic fields influence the sensor? According to reports, the sensor is barely influenced by magnetic fields. About customization How much can you downsize the sensing area? The minimum and the maximum sensing areas are determined by the maximum capacity. If the capacity ranges from 0.7 N to 6,900 N/cm², the sensing portion can be downsized to around 2 mm². How much can you enlarge the maximum capacity? If the capacity is 6,900 N/cm² or less, the capacity can be enlarged to around 10,000 N. Can you make custom sensors to be used in the ELF system? Yes, we can. Other questions What materials are suitable for the "Pack"? If the range to be loaded is wider than the pressure sensitive surface, it is necessary to use the "Pack (flat disc)". For the "Pack", a somewhat hard board with an area smaller than the pressure sensitive surface is used. Place this "pack" within the pressure sensitive surface, and apply a whole load onto the surface. It is necessary to avoid placing the "pack" on the edge of the pressure sensitive surface. We recommend plastic as a suitable material for the "pack", while metal and rubber are acceptable. If you employ rubber, the sensitivity increases. On the other hand, if you employ metal, the sensitivity decreases.