uDL2 Technical FAQ

The uDL2 is a battery operated two channel data logger designed specifically for monitoring CP coupons. The uDL2 has an internal shunt enabling direct measurement of coupon AC and DC current. A reference cell input provides DC potential, AC voltage and Instant-disconnect DC potential measurements. The uDL2 can also be operated in dual potential mode for monitoring two structures to a common reference point.
The uDL2 can be configured to take measurements from every 1 second to 12 hours and can store up to 2,000,000 readings.

Unfortunately, no. The current range must be selected in the uDL2 Configuration Editor when configuring the uDL2.

It is 1.01ohms total.

A fully charged battery is rated to last for 4 months or until the memory fills up, whichever happens first. Battery life can vary depending on the configuration of the uDL2, the condition of the battery, and the environment where the uDL2 is deployed.

The battery can be fully recharged in about 4 hours. However, the charge duration will vary depending on the battery condition and power source used. The battery icon in the top right corner of the LCD will flash while charging and will become sold once the battery is fully charged.

No. The uDL2 battery must be replaced at our factory. The useful battery lifetime is targeted to be 5-7 years.

You can check using the “Maximum Acquisition Time Estimate” function under the Help menu in the PC based uDL2 Configuration Editor. It gives you an estimated maximum data acquisition time before the data memory in the uDL2 becomes full based on the current configuration of the uDL2.
Note: The uDL2 may stop running before the estimated time if the uDL2 runs out of battery.

The uDL2 has two different measurement modes:

• Coupon Mode
• Dual Potential Mode

The way the uDL2 is connected will depend on the mode you have selected. The uDL2 analog measurement cables are color coded. You can find the color connection reference in the uDL2 configuration software as well as on the back of the uDL2.

Coupon Mode

Dual Potential Mode

Connect the uDL2 in series with the coupon. The uDL2 has an internal 1.01-ohm shunt allowing direct measurement of coupon AC and DC current.
Measuring across an external shunt with the uDL2 is not recommended as it could introduce inaccuracies. The potential measurement range of the uDL2 is designed for pipe to soil measurements rather than the small voltage drop across an external shunt.

Yes. The uDL2 takes the coupon current measurement and calculates current density using the configured coupon size. The coupon size must be entered in the uDL2 Configuration Editor.

The “SAMPLE” icon on the LCD will be displayed during each measurement. The icon will stay solid for the first minute after the analog cable is attached. Once the programmed timing conditions are met, the icon will start flashing accordingly each time the uDL2 makes a measurement.

No. The uDL2 can only delay the first coupon disconnect timing for up to 28 days after the first measurement takes place.

If you are taking the AC & DC measurements from a single coupon, then one uDL2 will collect all the data you require. If you are using separate AC & DC coupons, two uDL2s would be required to measure the current from each coupon.

Typically, the uDL2 should be installed with the cable facing down as the GPS antenna is located at the opposite end to the connector.

The uDL2 uses a low power LCD and it will stay on during its operation.

The uDL2 should be factory calibrated every 2 years, and every 5 years at most.

• Sampling Interval
  This setting will change how often the UDL2 makes a regular measurement (0-12hrs)
• Disconnect Cycle Period
  This determines how often the coupon is disconnected for instant-off and de-polarization measurements (0-28 days).
• Disconnect Duration
  This determines how long the internal relay is left open for instant-off and de-polarization measurements (0-28 days).
• Disconnect Holdoff
  This sets how long the uDL2 will wait before the first disconnect occurs after the first measurement is taken (10s-28 days).
• On->Off Simple Delay
  This sets the delay time of how long the uDL2 waits to take a measurement after disconnecting the coupon (0-1000mS).
• Off->On Disconnect Sample Delay
  This sets the delay time of how long the uDL2 waits to take a measurement after connecting the coupon (0-1000mS).

Follow the steps below to use the PC based configuration software to setup your UDL2 to measure coupon current density:

1. 1. Open the uDL2 Configuration Editor.
   2. Connect the uDL2 to your PC.
   3. Press “Read Config From uDL2”.
   4. Configure all settings as desired for timing and GPS etc…
   5. Select “Current” mode.
   6. Ensure “DC Enabled” is checked if you want to measure DC current density.
   7. Ensure “AC Enabled” is checked if you want to measure AC current density.
   8. Select the appropriate range. (See “Q. What are the measurement ranges of the uDL2?”)
   9. Select units of “A/m²”.
   10. Press the “Coupon Area (m²)” button to bring up the Coupon Area Converter window.
   11. Enter the area of the coupon.
   12. Select the units for the coupon area.
   13. Press the “OK” button. The software will automatically populate the Coupon Area field.
   14. Press “Write Config To uDL2” to save the changes into the attached uDL2. 
   15. Connect the measurement cable to start making measurements.

Follow the steps below to configure the uDL2 to measure DC current:

1. Open the uDL2 Configuration Editor.
2. Connect the uDL2 to your PC.
3. Press “Read Config From uDL2”.
4. Configure all settings as desired for timing and GPS etc…
5. Select “Current” mode.
6. Select the appropriate range. (See “Q. What are the measurement ranges of the uDL2?”)
7. Select “A” for the units.
8. Press “Write Config To uDL2” to save the changes into the attached uDL2.

Set both “Disconnect Cycle Period” and “Disconnect Duration” to 0.

If you do not require high accuracy GPS timing, selecting this option will use less battery power. The uDL2 will not periodically resynchronize with GPS time when this option is selected.
You should select this option if the uDL2 will be deployed in an environment where there is no GPS signal. An example of this being inside a metallic enclosure in a building. If this option is not selected, the uDL2 will keep attempting to synchronize with GPS time, draining the battery rapidly.

Enabling this option will invert the polarity of the measurement. If you would like the readings to be referenced differently, you can check the “Inv. Polarity” check box. For example, if you would like the potential measurements to be referenced from the reference cell in Coupon Mode, you could check the box in the uDL2 Configuration Editor, and the potential readings would be inverted. The diagrams show the polarity of the uDL2.

Follow the steps below to view the data preview graph in the uDL2 Configuration Editor.
Note: If the master data file is already extracted, start from step 2.1. 

1. 1. Open the uDL2 Configuration Editor and connect the uDL2 to your PC then press “Read Config From uDL2”.
   2. Press “Extract To Master Data File” to save the measurements to your PC.
      1. Press “Read Master Data File” and select the saved master data file from your PC. 
   3. Ensure the desired data file is displayed in the “Chart Title” box.
   4. Select the desired measurement type to generate the graph preview.

In Excel, the “Relay Enabled” Column will display the status of the disconnection relay when each measurement was taken. A “0” indicates the relay was open (disconnected).

The maximum number of rows that Microsoft Excel 2004 or newer can display is 1,048,756. You can use the Master Data File Split Utility to split the master file into smaller more manageable sized files.
Note: If the master data file is already extracted, then steps 1 and 2 can be skipped.

1. Open the uDL2 Configuration Editor and connect the uDL2 to your PC then press “Read Config From uDL2”.
2. Press “Extract To Master Data File” to save the measurements to your PC.
3. Press “Master Data File Split Utility” to open Master Data Conversion and File Split Utility window. 
4. Press “Select Source Master File(s)” to select the file you want to split.
5. Enter the maximum lines(rows) you want each file to have.
   Note: Enter the number 1048756 or less. 
6. Press “Split” to generate the split files. 

If you want to split the master data file into categorized separate files, follow the steps above to step 4, then

1. Select the desired readings group options you want to split the files into.
2. Press “Convert” to generate the split files.

If the “Require GPS Time Lock To Start Sampling” option is selected in the uDL2 Configuration Editor, the uDL2 will not start recording measurements until it acquires a GPS Time Lock. If the uDL2 is going to be deployed in a location where the GPS signal will be blocked, you should follow one of these two options.

1. Disable the “Require GPS Time Lock To Start Sampling” option.
   1. Select “Disable Long Term GPS Synchronization” to save battery consumption as there is no GPS signal once in the metallic enclosure.
   2. Press “Set uDL2 Clock” to synchronize the internal clock in the uDL2 to your computer’s clock
2. Select the “Require GPS Time Lock To Start Sampling” option.
   1. Select “Disable Long Term GPS Synchronization” to save battery consumption as there is no GPS signal once in the metallic enclosure.
   2. Move the uDL2 to a location with GPS coverage
   3. Wait for the uDL2 to acquire GPS Time Lock before moving the uDL2 back to the location with no GPS coverage (The LCD screen will display “Time Lock”).

Note: It may take up to 12.5 minutes to acquire a GPS Time Lock. 

There are few possibilities for this.

1. Ensure the battery if fully charged. It can take up to 4 hours to fully recharge the uDL2 battery. Check that the battery icon on the LCD is solid and no longer flashing to confirm charging is complete.
2. The GPS receiver may be running in the background where there is no GPS signal. 
   • Select “Disable Long Term GPS Synchronization” in the uDL2 Configuration Editor to stop GPS from waking up and attempting to resynchronize. 
3. The battery is reaching its end of life. The useful battery lifetime is targeted to be 5-7 years. Contact Mobiltex Service for battery replacement options

The uDL2 has limits for how low it can measure AC current in each range (AC Floor). Any values measured below the AC floor will be displayed as 0 in the data. Select an appropriate range for your measurement in the uDL2 Configuration Editor.

There are numerous possibilities. Here are few things you can check:

• Ensure that the uDL2 is configured correctly to measure current (See Q. How do I configure the uDL2 to measure current?).
• Check that the uDL2 is set to A vs A/m².
• Confirm the coupon size is correctly programmed.
• Ensure the range selected is appropriate for the measurement.
• Check for any physical damage on the analog measurement cables.
• Ensure the uDL2 is installed in series with the coupon. 
• Check if there is an external shunt connected to the coupon. If so, ensure that the uDL2 is in series between the coupon and pipe, not connected in parallel with the shunt. 
• Ensure you are connecting the correct color wires on the analog cable (see below).
• Check if the uDL2 was factory calibrated within the last 2 years.

Ensure the battery is fully charged. Confirm that the battery icon flashes when connected to USB and turns solid after a full charge. Check that the connector pins are not physically damaged. If the issue persists, contact Mobiltex Service.

Connect the uDL1 to your PC and re-install the latest firmware. If the issue persists, contact Mobiltex Service.

Call or email our tech support team. They can be reached toll free at 1-844-689-3282 – ask for Service. They can be emailed at service1@mobiltex.com.