Asked in Statistics
What is the difference between an error as a percentage of full scale or an error as a percentage of reading?
April 15, 2012 1:33PM
Error as a percentage of full scale is established by multiplying the error percentage by the full scale flow. The less you flow through the device the less accurate the reading will be. For that reason, you don't want to get a larger device than you need. Devices with error expressed as a percentage of full scale are most accurate when flowing at full scale.
Error expressed as a percentage of reading expresses error as a percentage of what the device is actually flowing. Simply, if a instrument's accuracy is rated to +/-1% of reading an instrument will be accurate to +/-1% of whatever the instrument is flowing. At 100SLPM the instrument will be accurate to within +/-1SLPM, and at 10SLPM of flow the unit will be accurate to within +/-.1SLPM.