'Wet' snow vs. 'dry' snow. The size and make up of a snowflake depends on how many ice crystals group together and this will be determined by air temperatures. Snowflakes that fall through dry, cool air will be small, powdery snowflakes that don't stick together.
What is calibration? Calibration is the activity of checking, by comparison with a standard, the accuracy of a measuring instrument of any type. It may also include adjustment of the instrument to bring it into alignment with the standard.
There are as many definitions of calibration as there are methods. the capability to adjust the instrument to zero and to set the desired span. accuracy of the instrument being compared. throughout the calibration range of the instrument.