Q: What is the difference between the Basic uDL1 and Advanced uDL1?

The Advanced uDL1 has additional features and functionality including:

  • Built in GPS
  • Periodic GPS clock synchronization
  • DC wave capture mode
  • Larger memory capacity
  • Interruption tracking (G2 model only)

Refer to the comparison chart below for further details:


Basic uDL1Advanced uDL1

Memory Size (samples)

500,0001,000,000 (G1) / 2,000,000 (G2)
Sampling IntervalBetween 1 second and 12 hours
  • Between 1 second and 12 hours
  • 10 times per second (DC Wave Capture mode)
  • Interruption Tracking (G2 only)

Q: What is the difference between the G1 and G2 Advanced uDL1?

The next generation of Advanced uDL1 utilizes new hardware with additional features. The primary improvement is the addition of interruption tracking. When this feature is enabled, you can program your interruption cycle parameters into the uDL1. The G2 uDL1 will record measurements during the On and Off cycles of your interruption survey.
The memory capacity for the Advanced uDL1 G2 is 2,000,000 samples (1,000,000 for the Advanced uDL1 G1). 

Q: What are the measurement ranges of the uDL1?

Low +/- 150mVDC, 110mV true RMS AC, 150mVpeak
Medium+/- 20VDC, 14V true RMS AC, 20Vpeak
High+/-150VDC, 106V true RMS AC, 150Vpeak

Q: What is the measurement accuracy of the uDL1?

DC Measurement Accuracy         

over -20° to +60° C (-4° to +140° F) 

  • low range: +/-0.25% + 100uV 
  • med range: +/-0.5% + 12mV 
  • high range (-75V to +75V): +/-0.5% + 100mV 
  • high range (<-75V and >+75V): +/-1% + 100mV 


AC Measurement Accuracy         

over -20° to +60° C (-4° to +140° F) 

  • low range: +/-0.3% + 80uV, 180uV floor 
  • med range: +/-0.65% + 10mV, 22mV floor 
  • high range (-75V to +75V): +/-0.65% + 80mV, 170mV floor 
  • high range (<-75V and >+75V): +/-1% + 80mV, 170mV floor

Q: Is the uDL1 auto-ranging?

No. The range must be selected in the uDL1 Configuration Editor when configuring the uDL1.

Q: What kind of GPS antenna does the uDL1 use? Can I attach my own antenna?

The Advanced uDL1 has a built-in internal GPS antenna. You cannot attach your own antenna onto the uDL1.

Q: How often do I need to calibrate the uDL1?

The uDL1 should be factory calibrated every 2 years and as a maximum every 5 years.

Q: Can I get calibration certificates for my uDL1s?

Mobiltex offers 3 different calibration certificate options for the uDL1:

  1.  Mobiltex issued calibration certificate (this is the same certificate that ships with the uDL1 when purchased new)
    Mobiltex/Cortalk Certificate of Calibration
  2. Mobiltex issued as found / as left readings
    As found/as left certificate
  3. Independent third party NIST traceable calibration certificate (we send the uDL1 to an independent lab for verification)


Q: What is the difference between Periodic Sample Timing, DC Wave Capture, and Interruption Tracking in the uDL1 Configuration Editor?

Periodic Sample Timing
Periodic sample timing is how often the uDL1 will record a DC, AC, or temperature measurement. This can be set between 1 second and 12 hours.

DC Wave Capture
When DC Wave Capture is enabled, the uDL1 will make DC only readings ten times per second. While the DC Wave Capture measurements are being made, other measurements (DC/AC/temperature/interruption tracking) will not be recorded. 

Interruption Tracking
When this feature is enabled, the uDL1 records on and off measurements that are synchronized with your programmed interruption parameters. In the extracted data, the on or off interruption state will be included with the measurements.
Note: The Interruption Tracking feature is available only for Advanced G2 uDL1’s. Interruption Tracking measurements will override the periodic sample timing.

Interruption Tracking Spreadsheet


Q: How long does the battery in the uDL1 last on a full charge?

A fully charged battery is rated to last for 6 months or until the memory fills up, which ever happens first. Battery life can vary depending on the configuration of the uDL1, the condition of the battery, and the environment where the uDL1 is deployed.

Q: How long does it take to charge the uDL1 battery?

The battery can be fully recharged in about 4 hours. However, the 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.

uDL1 battery indicator on empty

Q: Is the battery for the uDL1 field replaceable?

No. The uDL1 battery must be replaced at our factory. The useful battery lifetime is targeted to be 5-7 years.

Q: Will the battery for the uDL1 work when it is -10℃?

The operating temperature is rated at -20℃ to +60℃ (-4℉ to +140℉) but the recommended battery charging temperature is 0to +40 (32 to +104).

Q: How long will the uDL1 run before it runs out of memory with my configuration?

You can check using the “Maximum Acquisition Time Estimate” function under the Help menu in the PC based uDL1 Configuration Editor. It gives you an estimated maximum data acquisition time before the data memory of the uDL1 becomes full based on the current configuration of the uDL1.

Data acquisition estimate

Note: The uDL1 may stop running before the estimated time if the uDL1 runs out of battery.


Q: How can I tell if the uDL1 is making measurements?

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 uDL1 makes a measurement.

Sample icon

Q: Can I program the uDL1 to start recording at a particular date and time?

The uDL1 can be programmed to delay measurements by a specific number of minutes after the measurement cable is attached. The delay can be programmed up to 40320 minutes (28 days). The uDL1 will perform a one-minute sample preview once the analog cable is plugged in and then display “hLD” on the LCD for the programmed number of delay minutes.

Q: How does the uDL1 measure current?

The uDL1 can measure the voltage across an external shunt and convert it to current using a programmed scaling factor. The scaling factor can be calculated by pressing the “Shunt Calc” button and entering the shunt values.

uDL1 current measuring

Q: How long will it take for the uDL1 to get GPS time lock?

It can take up to 12.5 minutes for the uDL1 to get a GPS time lock. “TIME LOCK” will appear on the LCD once a GPS Time Lock is acquired.

Time Lock

Q: Can the uDL1 record both AC volts and amps measurements at the same time?

No. The uDL1 can take AC volts and DC volts measurements at the same time, but it cannot take volts and amps measurements at the same time.

Q: Should I leave the uDL1 with the cable side facing up or down?

Typically, the uDL1 should be installed with the cable facing down as the GPS antenna is located at the opposite end to the connector.

Q: I am waiting for the LCD to turn off. When does the LCD turn off?

The uDL1 uses a low power LCD and it will stay on during its operation.


Q: When do I use the “Disable Long Term GPS Time Synchronization” option?

If you do not require high accuracy GPS timing, selecting this option will use less battery power. The uDL1 will not periodically resynchronize with GPS time when this option is selected.
You should select this option if the uDL1 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 uDL1 will keep attempting to synchronize with GPS time, draining the battery rapidly.

Q: I have an older advanced uDL1 (non-G2). How can I set it up to record On and Off measurements with an interruption cycle of 1.5 seconds on, 0.5 seconds off?

You can configure your Advanced uDL1 G1 to take a sample every 1 second and apply a 250ms offset. This would capture one sample during the on interval and one sample during the off interval. The data would include a time stamp and the measurement in AC or DC or both.

Another option is to enable the DC wave capture mode in Advanced uDL1’s. The fast-sampling rate of a DC measurement every 100ms will capture numerous readings during each on and off cycle. 

Note: The data will not include an indication if the measurement was made during an on or off cycle. If an on or off indication is required, an upgrade to a G2 model will meet this requirement.


Q: How do I extract the measurement data from the uDL1 and view a graphing preview in the Configuration Editor?

Follow the steps below to view the data preview graph in the uDL1 Configuration Editor.
Note: If the master data file is already extracted, start from step 2.1.

    1. Open the uDL1 Configuration Editor and connect the uDL1 to your PC then press “Read Config From uDL1”.
    2. Press “Extract To Master Data File” to save the measurements to your PC.
    3. Press “Read Master Data File” and select the saved master data file from your PC. 
    4. Ensure the desired data file is displayed in the “Chart Title” box.
    5. Select the desired measurement type to generate the graph preview.

Measurement graph preview


Q: Why is the Interruption Tracking box greyed out in the uDL1 Configuration Editor for my Advanced uDL1?

Interruption tracking is only available on the 2nd generation G2 uDL1 model. You can view the generation of the unit at the bottom right of the uDL1 Configuration Editor.

uDL1 product generation

Q: Why is the polarity of my readings inverted?

Ensure that the connections are made correctly; red is positive, black is negative. Check that the scaling factor is not set to negative 1 (-1) in the uDL1 Configuration Editor.

uDL1 Configuration editor with scaling set to 1

Q: I took a large number of readings but not all the extracted data appears in Excel.

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 uDL1 Configuration Editor and connect the uDL1 to your PC then press “Read Config From uDL1”.
  2. Press “Extract To Master Data File” to save the measurements to your PC.
  3. Press “Master Data File Split Utility” to open the file Split Utility window. 
  4. Press “Select Source Master File(s)” to select the file(s) you want to split.
  5. Select the desired readings group options you want to split the files into.
  6. Press “Convert” to generate the split files.

Master data file split utility

Q: My uDL1 is recording the time stamps differently in the extracted data compared to the actual time when the measurements were taken.

UTC time may be selected for the extracted time instead of local time in the uDL1 Configuration Editor. 

If the UDL1 is a basic model (no GPS), ensure that the uDL’s clock is set by pressing the “Set uDL Clock” button before deploying the uDL1. This will sync your uDL1’s clock with your computer’s clock.

For Advanced uDL1s, check the GPS configuration and confirm the “Time Lock” icon on the LCD of the uDL1 is displayed to confirm the uDL1 has Synchronized with GPS time.

Setting time using the uDL1 configuration editor

Q: I deployed my uDL1 in a metallic enclosure and it didn’t record any measurements. When I retrieved the uDL1, it was still running.

If the “Require GPS Time Lock To Start Sampling” option is selected in the uDL1 Configuration Editor, the uDL1 will not start recording measurements until it acquires a GPS Time Lock. If the uDL1 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.
    – Select “Disable Long Term GPS Synchronization” to save battery consumption as there is no GPS signal inside the metallic enclosure.
    – Press “Set uDL1 Clock” to synchronize the internal clock in the uDL1 to your computers clock
  2. – Select the “Require GPS Time Lock To Start Sampling” option.

– Select “Disable Long Term GPS Synchronization” to save battery consumption as there is no GPS signal inside the metallic enclosure.
– Move the uDL1 to a location with GPS coverage

– Wait for the uDL1 to acquire GPS Time Lock before moving the uDL1 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.

uDL1 configuration editor (GPS time lock)

Q: I took AC and DC voltage measurements with my Advanced uDL1. Why do I only see DC voltage measurements in the extracted data file?

Check if DC Wave Capture mode is enabled. While the uDL1 is in DC Wave Capture mode, normal sampling of DC/AC/temperature is suspended (including interruption tracking measurements).
In Excel, expand the Record Type column to display record type fully and look for the desired record types. You can also use this filter function to only display selected measurements.

Excel Record Type column (collapsed)Excel Record Type column (expanded)

Q: The battery is being depleted faster than I thought it would. What could be the issue?

There are few possibilities for this:

  1. Ensure the battery is fully charged. It can take up to 4 hours to recharge the uDL1 battery. Check that the battery icon on the LCD is solid and no longer flashing.
  2. The GPS receiver may be running in the background where there is no GPS signal.
  3. Select “Disable Long Term GPS Synchronization” in the uDL1 Configuration Editor to stop GPS from waking up and attempting to resynchronize.
  4. 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.

Q: My uDL1 seems frozen and is displaying “loAD” on the LCD.

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

Q: My uDL1 does not turn on with the measurement cable but works with the USB cable attached.

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.

Q: I am still having issues, how can I get tech support?

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


Call toll free: 1 844 689 3282 [NA]
1794 340515 [UK]

Our industry-leading Sales, Technical Support, and Service teams are ready to take you from product selection to initial set-up and continue to provide dedicated support throughout the product lifecycle.