When connecting the VW Crack Meters or Joint Meters wires to the data logger, the wires should be connected to the proper terminal positions on the terminal block.
SH – Shield wire
C2 – Black wire
C1 – Red wire
T2 – Green wire
T1 – White wire
There is a YouTube video available https://www.youtube.com/watch?v=a5hHQaN1NkI that demonstrates the process.
The manual for the VW Crack Meter and Joint Meter are at the links below and should referenced before and during the installation of the sensors. There is information in the manuals that is used for assisting the user in calculating the displacement from the raw B Units recorded by the sensor.
https://rstinstruments.com/wp-content/uploads/EXM0036N-Vibrating-Wire-Crack-Meter-Manual.pdf
https://rstinstruments.com/wp-content/uploads/vw-jointmeter.pdf
- Connect to the DT2011B Data Logger with the DT Logger Host Software.
Per the photo below on the Connections tab, choose Options>Advanced to set the battery type and initialize the battery. This should also be done when the battery is changed. Check the Use Resistance Scaling box. Make sure to remove the battery tab from the data logger before leaving the site as the data logger will run off the power supplied by the USB cable until it is disconnected.
2. Move over to the Sensors Tab on the left sideof the header. If desired, change the header to the serial number of the VW Crack Meter and Joint Meter that is connected, or to the operators prefered description (ex. VM1229).
- Use “Normal (1200-3550Hz)” for the sweep setting.
- If you wish to see the displacement in engineering units, check ‘Enable Engineering Units” and choose either the Linear Method or Polynomial Method for the conversion factors. These value are on the Calibration Record for the Crack Meteror Joint Meter.
- The initial B Unit readings are taken when the sensor is installed.
- The temperature correction factor does not apply to the
- Choose the Units Conversion and select Distance, the milimeter input and output will auto-populated, but the output can be changed.
- If desired, click in the Display Format button to choose the decimal digits.
- Click on Upload To Logger to save the selections.
- If there is existing data in the data logger, it will be erased when the sensor information is updated.
Linear Conversion
Polynomial Conversion
3. To set the data logger collection interval, go to the Logger tab.
- Set the prefered interval
- Choose the start time for the data logger to collect the first reading. (it is a good idea to take some preliminary readings at 1 minute intervals to verify it is working correctly. Sync to Interval will start the data logger at midnight. The operator can choose a specified Start Time or Start Now.
- The clock can be synced to the computer or manually set.
- Memory Options will allow the data logger to overwrite older data or stop when it is full.
- For any changes to be programmed, the operator must press the Apply Settings button.
- When logging onto the data logger, the Status screen is the first to appear. It will display programmed information and show the current state of the data logger and battery information. To download the data from the data ;logger, click on the Collect Data button. The data is stored in the directory designated in the Connections tab, this can be changed by the operator.
For assistance with data interpretation and conversion of readings, please refer to the Embedment Strain Gauge Manual on pages 9-13 at the link below.
https://rstinstruments.com/wp-content/uploads/2020/04/embedment-vw-strain.pdf