Certain radio frequencies have been allocated for radio telemetry purposes with restrictions on the type of data sent. For example at 458 MHz there is a band dedicated to telemetry, the transmit power is restricted to 500mW and therefore the range is limited to approx 20 kilometres.
The time between data samples being taken. For example in a vendor managed inventory application the log interval could be say 30 minutes, meaning that the level of the tank is measured and recorded every 30 minutes
A level sensor is used to measure the volume of product within a storage tank. There are different techniques available, such as hydrostatic and ultrasonic. Different applications require different solutions. The actual height of the product is measured and then converted into volume by data acquisition software.