The difference between the reference and a sample is that the concentration of the measurable substance in the reference solution is zero. The reference tube transmits as much light as is possible with the solution you are using.
Rate this Article: The Saffir-Simpson Hurricane Scale is a 1-5 rating based on the hurricane's present intensity. This hurricane scale is used to give an estimate of the potential property damage and flooding expected along the coast from a hurricane landfall. Wind speed is the determining factor in the scale, as storm surge values are highly dependent on the slope of the continental shelf in the landfall region. Wind speeds are measured using a 1-minute average. Note:The Saffir-Simpson Hurricane Wind Scale (SSHWS) was updated in 2012 to accomodate number rounding issues.
Tornado strength is currently measured on what is called the Enhanced Fujita Scale (adapted from the simpler Fujita Scale in 2007), which gives the tornado a rating from 0 to 5 based on estimated wind speeds and the severity of the damage.