Olpas Citizen Science
Open hardware and software for non-profit and educational purposes.
Supporting citizen science aligned with Olpas' environmental values.
Project OpenTholoMetri
The OpenTholoMetri project describes a data logging system with turbidity measurements using optical sensors. The sensor contains two different optical sensors and an accurate temperature measurement. The system operates in a low-power mode, periodically waking up to take sensor readings, logging the data to an SD card with timestamps, and then returning to sleep. In a simple PVC housing the OpenTholoMetri sensor is a fully stand-alone system for measuring water quality.
Turbidity Sensor
OpenTholoMetri
OpenTholoMetri is heavily inspired by the OpenOBS-328 project by Ted Langhorst, and optimised and documented for Citizen Science usage by David Maat while working for Thomas More Digital Innovation.
Highlights of OpenTholoMetri
OpenTholoMetri is an economic Optical Backscatering Sensor, measuring Turbidity and Temperature.
The device can be build using off-the-shelve materials, for less than € 75.
It has a battery, real-time clock (RTC) and supports datalogging on SD-cards.
Measurement methodology
Optical Backscatter (OBS)
The OBS sensors consist of a high intensity infra-red emitting diode, a detector, and a linear, solid state temperature transducer. Optical backscattering provides an indication of suspended sediment (SSC) in water.More info about this sensor type: See the Coastal Wiki
Turbidity
Optical Attenuation
Besides optical backscattering, the turbidity of water is measured using attenuation of light coming from the light source to the light receiver. This method is highly suitable for organic matter suspended in water.
Project OpenSpatioMetri
The OpenSpatioMetri project describes a simple level sensor for surface water based on a 24Ghz radar. The sensor includes wireless LTE communication by default and operates on 4 rechargable AA batteries.
Level sensor
OpenSpatioMetri
Measuring water level is the start in understanding rivers, streams and nature. To capture long-term effects, the level sensor operates for prolonged time on rechargable batteries and wireless data communication is included.
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