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.
A few notes on using this PPS signal: 1  There are two measures of the signal: one is the signal accuracy and the other is its precision. Accuracy is how close the signal edge is to the actual UTC boundary. 2  The PPS signal edge and rise time are very important if you are using it to reset a counter. If the rise time is slow due to a large input capacitance, long signal length, etc. this will add an offset to the accuracy that will need to be calibrated out.