• Small size, light weight & large memory capacity
  • High resolution
  • Non-volatile flash memory
  • Built-in calendar / time information
  • No interface required
  • Programmed calibration factors
  • Wiper function provided as standard
  • Better stability & longer life span
  • No corrosion due to titanium housing
  • Easy-to-use data acquisition software (Windows version)

One-month deployment under burst interval of 10 minutes

Compact-CLW is a miniature and precision data logger with a micro-controller suitable for long-term consecutive deployment. Our updated state-of-the-art technology allows for a compact design capable of storing up to 179,178 sets of 4-channel data, consisting of chlorophyll, turbidity, temperature and battery voltage. This facilitates up to one year of continuous measurement.
The memory media, non-volatile flash-memory IC's, protect data from loss resulting from irregular battery voltage. This feature improves reliability.
A circular array of light emitting diodes (LED's) provides the excitation light for the chlorophyll-a fluorescence and the turbidity backscatter sensors. Optical filters in front of the optical receivers separate the backscattered light (turbidity) from the fluorescence signals. The filters also prevent the influence of solar light on the measurements.
A wiper sweeps the optical surface before each sample to remote dirt and residue. This improves the repeatability of the measurements and makes long-term deployments possible.
The turbidity sensor has a superior stability in low concentration areas and the correlation with suspended sediment in high concentration areas has been improved. The instrument, therefore, can be used not only in the marine field but also in river and dam applications.
Compact-CLW is controlled through the PC serial port, RS-232C. The main unit records calendar and time information with each sample and the sensor's calibration coefficients are stored in the built-in memory. The basic measurement setup requires only the selections of the start time and the sampling interval.
The data transfer after the completion of the deployment is easily accomplished. Information, such as measurement start time and calibration coefficients, are transferred together with the measured data. The user is free from troublesome coefficient control. Data can be processed quickly and effortlessly.
The data processing program offers clear and logical screens for easy operation.

Measuring Items Chlorophyll Turbidity Temperature
Sensor type Fluorescence light
Infrared back-scattering Thermistor
Measurement range 0 to 400 ppb
based on Uranine solution concentration
0 to 1000 FTU
based on Formazine solution concentration
-5 to 40 XC
Resolution 0.01 ppb 0.03 FTU 0.001 XC
Accuracy 1 % of measured value Zero drift 0.1ppb Temp. deterioration -0.125 % / XC 2 % of measured value Zero drift 0.3FTU Temp. deterioration -0.125 % / XC 0.05 XC
Memory type 2 MB flash memory
Memory capacity 179178 data sets
A/D converter 16-bits digital conversion
Measuring Interval 0.5,1,2,5,10,15,20,30 seconds
Burst time 1 to 1440 minutes adjustable per minute
Sample number 1,10,15,20,30,60,120,180,240,300,600,1200
Battery capacity Lithium battery (14 Ah)
Material of outer case Titanium
Weight 1080 grs in air, 560 grs in water.
Depth rating 200 m