Frequently Asked Questions
Oscillo gives you two complementary tools: the Timegrapher for acoustic snapshots of your movement, and the Precision Log for real-world drift on the wrist. Here's how they fit together — and why the numbers can look different.
What's the difference between the Timegrapher and the Precision Log?
They measure different things over different time scales.
The Timegrapher analyses your watch's tick sounds in real time. Hold the watch near your iPhone microphone and Oscillo computes rate, beat error, and amplitude from the acoustic signal. It's a snapshot of the movement's behaviour in one position, over a few seconds — the same kind of reading a watchmaker gets on a Witschi bench.
The Precision Log measures how your watch actually keeps time as you wear it. You log the time the watch is showing — once a day, once a week, whenever is convenient — and Oscillo computes the observed rate across that cycle: how many seconds per day it gained or lost in real life. Because the watch is on your wrist the whole time, the log captures everything the Timegrapher can't: positional changes, temperature, power reserve curve, magnetism, and shocks.
Use the Timegrapher for a fast diagnostic. Use the Precision Log to know how your watch really performs.
Why does my watch gain or lose a different amount on the wrist than what Oscillo shows?
A timegrapher measures rate in a single, static position over a short period. On the wrist your watch constantly shifts between positions — dial up, crown down, and everything in between — each of which can have a slightly different rate. The cumulative effect of all those position changes throughout the day produces a different result from any single reading.
The Precision Log is designed to close this gap: by recording the time the watch actually shows after days of wear, it reports the rate your watch is really keeping in your life — not just in one position on a desk.
How do positional differences affect accuracy?
Gravity acts on the balance wheel differently depending on whether the watch is lying flat or standing on edge. Most movements show a spread of several seconds per day across the six standard testing positions (dial up, dial down, crown up, crown down, crown left, crown right).
Professional watchmakers regulate a movement by finding the best compromise across all positions. A timegrapher reading in one position only tells part of the story.
Tip: Take measurements in more than one position to get a fuller picture of your movement's behaviour. Try dial up (overnight resting position) and crown down (common wearing angle).
Does mainspring tension matter?
Yes — significantly. A fully wound mainspring delivers more torque, which typically increases amplitude and can shift the rate. As the mainspring unwinds over the day the amplitude drops, and the rate may change with it. This effect is called isochronism error.
If you measure your watch right after winding, the reading may be faster than what you observe after 12–18 hours of wear when the power reserve is lower.
What role does temperature play?
Metal components in a movement expand and contract with temperature. Warmer conditions generally cause a watch to run slightly slower; cooler conditions have the opposite effect. On the wrist the watch is heated to near body temperature, whereas a desk measurement might be at a cooler room temperature.
Modern movements with Nivarox-type hairsprings are far less sensitive to temperature than older designs, but the effect is not zero — it can account for a second or two per day in some cases.
Can magnetism cause discrepancies?
Absolutely. If the hairspring has become even mildly magnetised, coils can stick together and shorten the effective length of the spring, causing the watch to run dramatically fast — sometimes minutes per day. A timegrapher will show this as an unusually high rate.
If your watch suddenly shows a large positive rate that doesn't match previous measurements, magnetism is a likely cause. A watchmaker can demagnetise the movement in seconds.
Does amplitude tell me something about accuracy?
Amplitude measures how far the balance wheel swings with each oscillation. A healthy movement typically shows an amplitude between 250° and 310° when fully wound in the dial-up position.
Low amplitude can indicate a worn mainspring, dried lubricants, or a dirty movement. It also tends to make rate less stable across positions. High amplitude (above 320°) can cause "knocking" where the impulse pin overswings and contacts the wrong side of the pallet fork, leading to erratic timekeeping.
How does beat error relate to daily accuracy?
Beat error is the difference in time between the tick and the tock — ideally zero, meaning the balance wheel swings symmetrically. A small beat error (under 0.5 ms) has negligible effect on rate. Larger values reduce the balance wheel's ability to self-correct and can make rate more sensitive to position and shock.
Beat error does not directly add seconds per day, but it worsens positional variation and reduces the movement's overall stability.
My timegrapher reading looks perfect but my watch still drifts. Why?
Several factors that affect daily wear are invisible to a timegrapher:
- Shocks and movement — wrist motion, impacts, and vibrations during daily activity can momentarily affect the balance wheel
- Crown-seal friction — a tight crown or worn gasket can slightly alter the mainspring torque curve
- Lubricant condition — dried or degraded oils increase friction unpredictably, especially in certain positions
- Power reserve depletion — timekeeping often worsens in the last quarter of the power reserve
- Wearing habits — an active day versus a sedentary day produces different positional averages
How should I interpret my Oscillo measurements?
Think of each measurement as a diagnostic data point, not a prediction of daily accuracy. Over time, consistent readings in the same position and state of wind give you a reliable baseline. If that baseline shifts noticeably, it's a sign that something in the movement has changed — lubrication, magnetism, or wear.
Best practice: Measure at the same time of day, in the same position, with a similar state of wind. This controls for variables and makes trends meaningful.
Why do I need a quiet environment to measure?
Oscillo works by listening to the faint tick and tock impulses of your movement through the device microphone. These sounds are very quiet — typically well below normal conversation level. Any ambient noise (music, traffic, air conditioning, keyboard typing, nearby appliances) can overlap with the tick signal and make it difficult for the DSP to distinguish impulses from background sound.
When background noise is too high, the app may fail to lock on to the tick pattern, produce unstable readings, or misidentify noise peaks as impulses — leading to incorrect rate, beat error, or amplitude values.
Tip: Choose a quiet room, turn off fans and music, and place the bottom of your iPhone (where the microphone is located) flush against the watch crystal. This direct contact transmits the tick vibrations clearly to the microphone and minimises interference from ambient sound. The quieter the environment, the cleaner the signal and the more reliable your measurements will be.
Is Oscillo as accurate as a professional timegrapher?
Oscillo uses the same DSP principles as professional timegraphers — listening to the tick sounds and measuring the interval between impulses. The quality of the measurement depends on microphone sensitivity and ambient noise. In a quiet environment with the watch positioned close to the microphone, results are comparable to what a watchmaker would see.
For the most reliable readings, measure in a quiet room with the watch resting on a soft surface near the device microphone.