WATER & SOIL | |S Electronic Tensiometers Ideal for automatic soil moisture measurement |S Suitable for soil, peat and other mediums |S No correction factors |S needed for different soils or mediums Easy top up without removal from soil |S Robust, corrosion free design |S Compatible with most dataloggers including |S Skye’s DataHog loggers and HydroSense meters Skye automatic electronic tensiometers are the acrylic head, which is then sealed with precision made devices for measuring soil an 'O' ring and screw. moisture pressure or water potential. They measure directly in HectoPascals (or mbar) These units can be left in situ and either the suction pressure required to utilise the connected to the Skye DataHog (or other water in the measured area, and hence the datalogger) or the Skye HydroSense for water available to the plant. continuous recording or instantaneous readings of soil moisture measurements. The head of the instrument, which houses the pressure transducer, is machined from Skye Instruments family of soil moisture acrylic and is fully sealed for outdoor use. measurement equipment, includes Mini The shaft, which is filled with water, is also Tensiometers, Analogue Dial Gauge of acrylic and again is fully sealed into the Tensiometers and Septum Tensiometers. porous ceramic bulb which allows the Please ask for separate datasheets for full transfer of water for the pressure to be specifications. measured. The shaft can be topped up, without disturbance of the soil, using a syringe and silicon tubing, via an aperture in SPECIFICATIONS Shaft dimensions Operating range Cable length Measurement range Output Details 20mm 0 to 70°C 0 - 850 hPa (0 - The tensiometer is fitted with a 3m standard low pressure transducer (Precautions 850mbar) (minus stabilised for temperature and (longer if required) required for shaft length - ie. For linearity. The output is screened cable ratiometric for excitation th le operation in below 30cm shaft length voltage, but is usually g b ne ria zero conditions) the range is 0 - 820 calibrated at 5 volts. The L a transducer behaves as a v hPa) ‘bridge’ type sensor and is suitable for connection to any m meter or logger with differential m voltage inputs. DataHogs and 05 the HydroSense are designed for these sensors. Excitation voltage Sensor excitation Typical output Typical calibration Linearity & hysterisis Voltage Data Error 1 to 15 volts DC 1.25mA at 5 volts 0-50mV D.C. At 5 1mV per 20 hPa at Typically less than volt excitation 5 volt excitation 0.4% to 50°C Thermal error Null offset shift Long-term stability Of span Typically less than Typically less than 0.1% per year 0.4% to 50°C 0.2mV to 50°C typically NOTES ON SPECIFICATIONS (1) Tensiometers require a stabilised power supply which is provided by the DataHog datalogger and HydroSense meter. Other dataloggers may not give a stabilised power supply. In this instance, an optional stabilised power supply can be built into the tensiometer ORDERING INFORMATION Tensiometers SKT 600 Series Electronic Tensiometers (lengths 20cm to 1metre) with 3 Skye Instruments Ltd metres cable 21, Ddole Enterprise Park Llandrindod Wells SKT 600/I Series Electronic Tensiometers with 3 metres cable and connector for Powys LD1 6DF DataHog or SpectroSense United Kingdom /S Stabilised power supply for electronic tensiometers TEL +44 (0)1597 824811 Loggers & Meters FAX +44 (0)1597 824812 EMAIL skyemail@skyeinstruments.com SDL 5000 Series DataHog loggers WEB http://www.skyeinstruments.com SKT 660 HydroSense logging meter Recommended Accessories TEN/5 Syringe and filling tube - recommended for filling and installing all tensiometers Document Outline Page 1 Page 2