土壤水份

TensioCheck

tensiocheck.jpg (34821 Byte) Electronic hand held measuring device with LCD-display and pressure gauge for measurement of the suction tension with tensiometers as well as testing of the switching points of electro-mechanical sensors (tensiostats). The advantages of the TensioCheck instrument for measuring suction tension are a higher degree of measuring accuracy, more accurate display (no read out errors), only one instrument necessary for many measuring sites, and capability of saving results.

Use:	No restrictions of moisture ranges or type of irrigation system, only for point measurements.
Accessories required:	Insertion tensiometer, possibly a testing kit for the Function Mode "Switching Control", possibly computer interface for reading out saved data.
Article number:	1700 TensioCheck

Technical Description

Housing: size-160 x 90 x 30 mm, plastic (ABS), with display dial and battery compartment on back side, protection type IP 40 (keep instrument dry); weight (including battery, without sensor)- 275 g; operation and adjustment by means of 4 input buttons lying beneath the clear plastic panel on front of instrument.
Display: size- 12.7 mm, 3編tellig, resolution- 1 hPa or 0.1 Ohm, display update- every 3/sec.
Memory: 104 positions (256 byte), safe in case of electrical failure, can be read out over PC with serial interface (available soon).
Measurement: measuring range- 0 ?1000 hPa, measuring frequency- every 5/sec in Function Mode "Suction Tension", every 25/sec in Function Mode "Switching Control", accuracy of measurement- < 0,5 % of the measuring range of sensor + display, typical accuracy- ?1-2 hPa; electrical resistance- 0 ?99,9 Ohm.
Electrical Supply: 4 x 1.5 V Mignon (Alkali) with battery control and automatic shut off feature, battery capacity- > 100 hours of operation.
Sensor: E-sensor Model CV with Luer-cone connection (screw-on connection GL 14 upon request); puncture needle- 0.5 x 12 mm Luer; connecting cable with 4 conductors, 100 cm long, with a miniature round plug with locking capability (turn-lock mechanism, type Binder).

Distinguishing Characteristics, Adjustment Possibilities

TensioCheck
Suction Tension

Basis for correct measurement is the exact setting of the zero point. Sensor deviations are automatically corrected upon activation of device or alternatively, later by hand (zero point key).
Digital input of a prededuction value (specific zero point correction value) allows for general calculation of the suction tension with the water column in the tensiometer; chosen prededuction value can be saved (4 values possible) and reused.
Saving the results: 100 memory locations, subdivided into 16 groups which can be saved under a specific number. The last 4 data can be directly displayed again, the rest can only be accessed over a PC.
The automatic shut-off (turns off after 5 min.) can be deactivated for the observation of dynamic suction tension processes, the TensioCheck remains on indefinitely, in this case.

TensioCheck
Switching Control

Checking the switching points of M-sensors:
The suction process is simulated using a suction flask. The switching-on and -off points are thereby slowly overlapped, the display then blinks and the respective values are saved. The pair of switching point values continue to blink alternately in the display, before a further test, they either can be deleted or saved for purposes of later comparison. The switching points can be adjusted according to instructions.
The electrical resistance can be measured at the same time or separately in a submode, in order to check if the switching contacts are still functioning electrically without any failures.

Accessories

Art. Num. Description	1701 Testing Kit	1702 TC-Interface
Parts	Threaded neck pieces GL 14 with 3 tube attachments (sockets + pieces of tube) + 2 suction flacks (1 ml, 2 ml) + connecting cable (50 cm) (for connection TensioCheck to M-Sensor)	Connecting cable for connection between TensioCheck and PC (1.5 m), with interface electronics including Software for Windows 95/98