5.1 Levelogger Information Settings

The Levelogger Information Settings window includes Levelogger identification, Project ID and Location fields, sampling settings, altitude and fluid density input fields. The following is a description of each of the fields:

Project ID, input your own Levelogger identification system. The Project ID is limited to 32 characters.

Location, input specific site / location information. The location is limited to 32 characters.

Altitude in feet or meters above sea level, at which the logger is actually deployed, is input in the altitude field. Water column equivalent pressure decreases with altitude at a rate of approximately 1.2:1000 in the lower atmosphere below 5000 m. You can compensate for this by entering an elevation between -1000 ft below sea level and 16,500 ft (or -300 m and 5000 m) above sea level. The readings will then be automatically compensated for elevation. The LTC and the L Levelogger (8.5”) have a maximum altitude input of 8190 ft and previous LT versions 9750 ft (3000 m). See Section 10 for more information on how the Levelogger and Barologger adjust for altitude.

Density Adjustment is used to adjust the range of the Levelogger based on the sample fluid density. The range for the density adjustment is from 0.9 kg/L to 1.1 kg/L. The range of the Levelogger after the density adjustment is based on the following formula.

Uncheck the Density Adjustment field to disable the Density Adjustment function.

Sample Mode, allows you to choose the sampling measurement type. Options are Linear, Event-based and Schedule (or Logarithmic in the older LT Leveloggers)

Memory Mode Selection will be grayed-out if not in Linear Mode sampling. When using a Levelogger Gold in Linear Mode, there is a choice of Continuous Logging (wrap around) or Slate Logging. In Continuous Logging the new log is started at the end of any previous log and continues logging, eventually recording over the first logged data. As one of the download options is to ‘Append Data’, Continuous Logging can be a preferred choice when logging long-term. In Slate Logging the new log is also started at the end of any previous log, but will stop recording after 40,000 readings, so that the beginning of the current log will not be written over.

Linear refers to a set time interval between collection of readings. Sample Rate can be any number from 0.5 seconds to 99 hours. The time unit and number of time unit intervals between each reading are set up in the Sample rate fields. The Levelogger Gold and Barologger Gold can store 40,000 readings of level and temperature. The LTC Leveloggers can store up to 16000 readings of level, temperature and conductivity. Previous LT Levelogger can store 24,000 readings.

Event-based Sample Collection is the most memory efficient means of data collection. In Event mode, the Levelogger will activate every sampling interval defined in Sample rate and check if readings have changed by the selected percentage (0.1 - 25% of Full Scale) from the last recorded reading. For Levelogger Gold and LT Leveloggers, level is the selected parameter where change is monitored. For LTC Leveloggers, conductivity is the parameter that triggers the event- base sampling regime. The Levelogger will record a new reading only if the specified change in level has occurred. Note that the percentage of change for sample collection is set in the Percentage field beside the Sampling mode and that the threshold change is a percentage of the Levelogger's Full Scale for that particular parameter. An important reminder is that, although actual memory usage in stable water level conditions may be relatively small, battery power consumption is partially a function of the sample reading rate. Therefore, a small sample reading interval will consume battery power at a higher rate whether readings are stored or not. In Event-based sampling mode, the Levelogger Gold has a total memory of 25,000 readings of level and temperature, the mini LT Levelogger (4.9 inches long) has a total memory capacity of 2 x 24,000 readings. The original LT Levelogger (8.5 inches long) will record 2 x 19000 readings in Event mode. LTC loggers will record 16000 readings in Event mode.

Figure 5-2 Levelogger Schedule Setup Window

Schedule Sampling in the Levelogger Gold, replaces Logarithmic sampling in earlier version Leveloggers. Select Schedule and click the Edit button in the Logger Settings screen to bring up the Schedule Setup Window. Buttons allow adding and deleting of lines, updating, opening and saving of *.sci schedule files. The maximum number of line items in a schedule is 30, each with its own sampling interval of seconds, minutes or hours and duration of seconds, minutes, hours, days or weeks. Running totals of the number of readings still available, from the total possible 40,000, and the run time to date are shown. If the number of readings selected exceeds 40,000 an error message appears. Schedule sampling allows the user to select a logarithmic style sampling schedule adapted to the needs of each application.

Logarithmic Sampling (available only on LT Leveloggers and previous Barologgers) offers a choice of three different sampling test periods with several levels of reading collection rates within each test period, based on a logarithmic spread of data collection intervals. The three Logarithmic sampling ranges are Log 25h, Log 6.5 day and Log 297 day sampling periods. Each log test starts with its most rapid sampling interval and uses a Step function approach in time to the longest logging interval at the end of the test. Figure 5.1 outlines how each Logarithmic sampling test period collects data over its entire sampling duration. In Logarithmic based sampling mode, the mini LT Levelogger (4.9 inches long) has a total memory capacity of 2 x 24,000 readings. The original LT Levelogger (8.5 inches long) will record 2 x 19000 readings in Log mode.