Temperature instruments and temperature indicators are designed for temperature monitoring and analysis. Temperature instruments and temperature indicators either come equipped with an integral sensor, or require sensor input.  Approximately 16% of all process instrumentation measures, indicates, or controls temperature. In many industrial applications it is necessary to collect temperatures as a permanent record due to government or manufacturing requirements, or to provide historical data that may later be used to determine problems within a system. Data collection methods in industry vary from simple manual systems using inexpensive portable indicators to sophisticated DCS (Distributed Control Systems) that both log and control data. The most inexpensive portable indicators do not provide any "recording" or memory features. Readings from portable temperature instruments and temperature indicators must be recorded by hand. Some portable indicators are available with memory so that a number of measurements may be collected and later downloaded into a personal computer.  A chart recorder is another device used to record temperature data.  These recorders usually offer digital readouts and give a digital indication of the process temperature of selected points or of scanned points. Distributed control systems also offer datalogging as a part of their overall capabilities. Since these systems are computer based, the datalogging functions are programmable to almost any needed configuration.