VII. Advanced Measurement Procedures
To suspend measurement, push the computer partially out of its mount to break contact with the sensor and freeze the display. Mark the wheel contact with the ground and note the rim reading. To resume measurement, reestablish the rim reading at the mark and push the computer all the way into its mount.
To avoid the requirement of noting the rim reading proceed as follows. Push the computer partially out of its mount and roll back the wheel to the zero point and mark it. To resume, establish the rim on the zero point at the mark, roll forward a partial revolution, and push the computer all the way into its mount. Measurers may not find this procedure intuitive, and it is probably better to always stop at a rim reading of 0.10 and use that described in the first paragraph.
Recently when using the Protege 5 and 9 I have noticed that, when electrical contact is re-established, the revolution display occasionally increments by one. I have never been able to elicit this response from the Protege 8 and it may never happen with any model if the counter is allowed to fall asleep first.
The fix is obvious: watch the display while re-establishing contact and make a correction if the display increments. Those measurers using the Sigma Sport magnet can avoid the problem by freezing the display in a different way. The magnet is simply twisted on the spoke so that it is furthest from the sensor side.
Suspending measurement has many useful applications many of which will be described in detail later:
1. Miscellaneous functions such as eating and recovering dropped objects.
2. Marking splits with paint and nails while retaining overall measurement.
3. Overshoot correction while retaining overall measurement.
4. Making secondary measurements using the second-wheel setting to correct for overshoot and to explore alternative routes.
5. Offset correction to avoid temporary obstructions.
6. Measurements close to the zero point while ensuring overall measurement is retained.
2. Recovering from sleep mode
If the sensor receives no impulses for five minutes the computer enters sleep mode in which only the clock is displayed. The computer can be awakened on receiving a impulse by simply riding off, but this impulse will not be recorded . Therefore to resume measurement, first awaken the computer by briefly pushing it forward in its mount.
3. Readings within a few hundredths of a revolution from the rim zero
Measurers can get confused as to what meter reading of whole revolutions to combine with rim readings within a few hundredths of a revolution of the rim zero especially if the meter is not precisely synchronized with the rim zero. To avoid this confusion note the meter reading long before the rim reading is at the zero point, Take the rim reading at the desired measurement point, and if this is before the rim zero, combined it with the previously noted meter reading. If it is after the rim zero combined it with the previously noted reading plus one.
To retain the overall measurement be careful to avoid rolling back when near the rim zero point. Alternatively, freeze the meter reading before reaching the region by pushing the computer back slightly in its mount. After making the rim measurement near the zero, move the wheel well back from the zero and reconnect the computer.
The simplest method of taking readings close to the zero point is to stop the bicycle with a rim reading of say 0.025 rev before or after and estimate what the rim reading is for the desired point. Combined this with the meter reading.
4. Obstacles
To correct for an obstacle, suspend measurement as described in 1 above and move the bicycle at right angles to the side of the road to clear the obstacle. Resume measurement until past the obstacle and then reverse the procedure back to the side of the road.
A cruder method is to lock the font wheel with the brake while dragging the bicycle out and into the side of the road at right angles.
5. Calibration simplification
On the first two rides of the calibration course make measurements as usual. However on the last two rides do not use the meter but assume the same number of whole revolutions as previously found. Simply start the wheel on the rim zero and note the rim reading at the end of the ride.
6. Secondary measurements
Sometimes in the middle of primary measurements it is useful to suspend these as described in 1 above and make secondary measurements. For instance different possible routes can be explored or a missed split can be located.
Suspend primary measurement as above and select the second wheel size by pressing the switch at the top right-hand side of the back of the computer. Since the circumference should also have been set to 9999, the computer is now ready to function as a secondary revolution counter.