If you don't use the computer interface, you have to rely on the MicroSet LCD screen to get a stable result. This is achieved by using the proper number in the TIME mode. For accurate readings you should use a multiple of the number of teeth on the escape wheel. This is because the eccentricity of the escape wheel is factored out when a complete rotation is included in each reading. This clock has a 25 tooth escape wheel. The graph below shows the clock measured with TIME: 50. In this graph, even the first readings are stable and accurate to a few seconds per day.

You might think you should use a TIME count of 25 for a 25 tooth escape wheel. But you should not use an odd number unless you're measuring one beat. An odd count will give you wildly changing results because of beat error in the clock.