To be deductible, a business expense must be both ordinary and necessary. An ordinary expense is one that is common and accepted in your trade or business. A necessary expense is one that is helpful and appropriate for your trade or business. An expense does not have to be indispensable to be considered necessary. It is important to separate business expenses from the following expenses:
A duple meter metronome that is useful for 2/4, 2/8, 2/2 (cut time), and 6/8 when it has two beats per measure.
What is the procedure and calibration of freezing point osmometry. a contemporary freezing point osmometer, a mechanism to supercool the sample slowly to about -7degC, a thermistor to monitor the temperature of the sample, a means to initiate freezing (or seeding) of the sample, and a direct readout display.