The second most common use of MicroSet is to measure the beat error of a clock or a watch. After you turn on the timer, press the MODE key twice to enter the Beat Error Mode. Then press BEGIN. MicroSet will measure the length of two beats and compare them. It will then display the difference between them. If the rate is fast, like a watch, the difference will be shown as a number of milliseconds:
- +12 ms
A plus sign will indicate that the first beat was longer than the second, a minus sign means the first beat was shorter. These signs are not very useful with watches, but can be very useful with clocks. If the rate is slower, like a clock, the result will be shown as a percentage:
A reading of 10% means one beat is 10% longer than the other. If the clock is in perfect beat, the error will be zero percent, but this is unlikely to occur. You will find that the beat error of clocks changes gradually as the escape wheel rotates. This is natural and is due to eccentricity in the escape wheel. The goal is to adjust the clock so the variation is small and is centered on zero. You can use the plus or minus sign to know which direction must be changed.