Calibration of the Ergometer

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In order to get precise test data, it is absolute necessary that the SRM – High Performance Ergometer is calibrated. We recommend conducting this calibration before every measurement.

PowerMeter Slope

Please check the slope on the PowerMeter and also on the SRMWin – Software before every test day. The proper setting is crucial for the measuring accuracy.

The slope is programmed into the PowerMeter and can be read from the back of the lid or the invoice and the delivery note.

If you are not able to read the slope anymore and you cannot find it somewhere else, please contact us under or by telephone and we will tell you the slope. We just need to know the serial number of your PowerMeter. This serial number is engraved on the front or back of the PowerMeter.

SRMWin – Software: Setting PC IV in the drop-down menu

Setting PC IV in the drop-down menu

The condition for the communication of the PowerControl IV (PC IV) with the installed SRMWin-software is the setting of the PC IV in the drop-down menu on the SRMWin surface.

SRMWin – Software: Setting USB/serial adapter in the active port

Setting USB/serial adapter in the active port

Please check if the accurate USB/serial adapter is installed correctly and also displayed on the screen. The installation and application of the provided adapter is necessary to guarantee correct data transfer to the connected computer. Furthermore, it is important that you install the matching adapter for the Windows version you are using.

If a compatible adapter is installed you can see it as “SRM Downloadcable USB” in the active port.

  • Our tested recommendations are:
ATEN USB-to-Serial-(RS 232) Converter, (Model: UC-232A), (up to Windows 7)
Plugable USB to RS-232 D89 Serial Adapter (up to Windows 8)
Delock Adapter USB 1.1 > 1 x Serial (up to Windows 10)

SRMWin – Software: PowerControl Setup

PowerControl Setup

Check the setup of the PowerControl by calling up the point PowerControl -> “Setup” in the SRMWin – Software.

  • Initials
Here you can define and enter for example the initials of your Ergometer. These initials determine the register on the harddrive of your computer in which the data will be saved (e.g.: _data.srm/_USA.srm). You can change the initials of already saved SRM files under Properties.
  • Interval of storage
The recommended storage interval in the PowerControl is 1sec. It will save an average value during the adjusted interval.
The data of the PowerControl can also be saved in intervals of 0.10s, 0.20s, 0.50s, 1s, 2s, 5s, 10s, 15s, 30s, 60s, 120s and 240sec (Interval of storage). If you want to readout the data and transfer it to a connected computer, you can only do that via the SRMWin-Software over Save Data F11.
  • Slope of Powermeter
Here you can adjust the slope of your PowerMeter (Reading the slope). In the images on the right hand side the PowerMeter has a slope of 15.85 Hz/Nm. The setting of the right PowerMeter slope is crucial for the measurement accuracy. A wrong setting of the slope results in incorrect power display.
  • Circumference of tire
The circumference of the tire for the Ergometer is set to “1000 millimeters”. This predetermined value of 1000 mm has to be maintained to guarantee the precise measurement of your power data.
  • Total distance
The overall distance which you have ridden with the PowerControl until now.
  • Training zones
Training zones
In this window you can set your personal training zones. These zones are independent from the analyzing of the training-zones which were set in the software. They just apply for the PowerControl and are recalled during training.
  • Date and time
Date and Time
With this button you can set date and time of the PowerControl. It is important to check these settings because the date is simultaneously a part of the file name and enables the assignment to a register in the database.
  • Special
Interval of storage for temperature
This setting has the purpose of saving the temperature over a certain time interval in the PowerControl. The time interval is shown in min.
Advisable would be an interval of 10 min. A shorter interval is not to recommend because the temperature sensor in the case of the PowerControl accommodates itself with a certain delay onto the ambient temperature.
Powercontrol display data
Update every: Tells you in which time interval the data will be updated on the display..
Smooth over: Tells you in which time interval the data will be smoothed on the display.
Example: The setting of 1 [s] at “Update every POW” (Power) and smoothed (Smooth over) over 3 [s], means that your PowerControl shows you every second the average power value over the last three seconds. These setting are independent of the interval of storage ones.
The label/time units are shown in seconds (s).
Measure heartrate also without other data
Usually, the PowerControl switches off if the speed and the cadence fall to zero. But you can choose the option that the PowerControl stays on to display the heart rate.
Powercontrol will not switch off
The PowerControl will not switch off and stays on until the batteries show not enough capacity anymore.
Highest change of heart rate
Highest change of heart rate per minute. If there are higher heart rates as the set ones they will be ignored.
Shortest heart rate transmitter signal
Shortest heart rat transmitter signal given in milliseconds.
  • Clear Memory
Please check in regular intervals the storage capacity (remaining memory) and the state of charge of the PowerControl via pressing the buttons MODE and PRO on the PowerControl simultaneously. The remaining memory is shown in percentage. If the memory is full, you should delete the data via "Clear memory".
All files will be irrevocably deleted.

Zero offset calibration of the PowerMeter

Zero offset calibration of the PowerMeter

The PowerMeter delivers a certain frequency which is proportional to the torque of the pedal force on the crank. If there is no load on the crank, the PowerMeter is sending a base frequency which must be communicated to the PowerControl as a reference value. This procedure is called zero offset calibration (offset adjustment).

The zero offset calibration has to be done before every new assembly of the PowerMeter and also before every measurement resp. every training on the Ergometer. A wrong zero offset calibration can result in an internal miscalculation of the power.

Please perform the zero offset calibration as it is described below:

  • For a manual comparison, please turn the right unloaded crank clockwise to activate the PowerMeter.
  • By simultaneously pressing MODE and SET, the PowerControl turns into calibration mode.
  • Wait a few seconds until the value on the right-hand side of the display stabilized itself.
  • Press SET to apply the zero offset.
  • The number on the right-hand side of the display is the current frequency of the PowerMeter (SET).
  • The number on the left-hand side of the display is the frequency which is used for the power measurement (MANU).