LogDator - Introduction

LogDator™

Under-water data logger — NEW: Master mode

For environmental monitoring as network master, slave, or stand alone

The LogDator™ (LD-02-00) is ideal for collecting data from one or many SediMeters, but it can also be used separately with its own sensors. Its small form factor and low power consumption makes it ideal for underwater use. It can return data immediately on a serial communication line, save data to internal memory, or save data to file on a memory card.

There are 2 A/D ports where OP-AMPs can be used for signal processing before the A/D converter. In other words, there are two channels for optional analog sensors, and they can be made to measure resistance, voltage, or current. These can be sampled up to 84 times per measurement, with a user-selectable frequency. Wave periods can be estimated from these data. Each measurement is the sum of 16 discrete measurements by the 12-bit A/D converter, an anti-aliasing method that results in 16-bit values. By taking 84 such samples very precise averages can be calculated, even from sensors with large random variations, e.g., pressure sensors.

Optional sensors that have been interfaced to the LogDator™ include: light sensor; pressure sensor for water depth, atmospheric pressure, or for measuring evaporation in an evaporation tank; and a sensor for relative humidity in a meteorological measurement station.

The user interface consists of the NavPin thumb control, with four directions plus select, together with a small display. This can be used to set date and time, start time, measurement interval, mode, etc. There is also a magnetic switch, which can be operated without opening the instrument, even under water. It is used to change mode, so that the instrument can be set up in advance, left in Sleep mode, and started under water. The connecters can be plugged in under water, and logging can be started under water.

The LogDator™ works with the SediMeter computer software for setup, download, data analysis, and real-time monitoring. Just like the software, the LogDator can now, from firmware rev. 2, be the network master that controls and gathers data from hundreds of slaves. To save power in stand-alone networks the LogDator issues a sleeping pill, so most of the time the units are in a very low power mode. Data from every slave is written to a separate file on the memory card, why also third party slaves can be used regardless of what data they send.

Another improvement is that conversion to physical units now are done in firmware. The specifications for the optional sensors can be changed from software via USB, so it will be possible to change sensors and adjust the firmware for anyone with access to the appropriate software.

LogDator network and stand-alone UW data logger

The LogDator™ underwater data logger can record data from its own optional sensors, and from up to 254 connected slaves, where each slave can have many sensors. The logger can be plugged in and measurements started under water. The display gives the diver feedback on network operation, battery condition, etc.

Since the LogDator™ can be set up for logging using the built-in user interface, and the data can be retrieved by exchanging the memory card, no field computer is required. Backlighting is on in this photo.

LogDator™ (LD-02-00) with optional sensors for pressure (LM-08-01) and light (LM-07-01).

This LogDator™ underwater network temperature logger (LD-01-00) supports temperature measurements, RS-485, has 2 MB memory, and 2 UW connectors. Other custom solutions can be offered on request. (Specifications)