218-AVS-30 Model SR Automatic Switch 18" (45cm) | Irrometer Soil Moisture Sensors
- The "SR" Irrometer is the standard instrument for use in medium to heavy soils.
- Instrument includes a threaded replaceable tip as well as reservoir, air free gauge chamber and hermetically sealed IRROMETER vacuum gauge with dual scale of centibars and kilopascals (0-100 cb [kpa] range).
- The white tipped STANDARD (SR) is for general use with row, tree, and field crops, with ranges from 0-100 cb (kPa).
- Default output setting: 30 centibars AVS (automatic vacuum switch)
- The Automatic IRROMETER provides direct switching capabilities thereby allowing the user to control irrigation events.
- The switch can control a single valve, a group of valves, or the entire irrigation controller.
- Ideal for managing irrigation based on soil moisture depletion.
Note: A Service Unit is necessary for proper operation of the IRROMETER® instrument and should be included on initial orders. One unit will service ALL of your IRROMETERS:
- The Standard Service Unit (1001) is used during initial installation and then periodically for removal of air from instrument to ensure maximum sensitivity and accuracy.
- The Test Pump Service Unit (1002) serves the dual purpose of removing air and testing the gauge in one operation.
Product Overview
The Tensiometer is the only direct measurement system available, which means that it actually reads the physical forces at work in the soil. Tensiometers act like a dummy root, allowing the soil moisture to interact with the instrument through the ceramic tip. Soil water tension outside of the instrument tries to remove the water from it, which creates a measurable tension inside the column. This tension is read with either a mechanical gauge or a transducer attached to the instrument. While this is the most accurate and proven method available, there is some maintenance required periodically to keep them full of water, and they must be removed from the field during the winter months to avoid freezing.
- IRROMETER® measures soil water tension which indicates plant water availability.
- The IRROMETER Tensiometer is the standard in accurate soil moisture measurement, offering growers an inexpensive and reliable means of measuring soil moisture for irrigation scheduling.
- An IRROMETER will measure the actual soil water tension, which indicates the effort required by root systems to extract water from the soil.
- Because the IRROMETER is a true measurement of soil water potential, the instrument is not affected by salinity and does not require site calibration.
- The IRROMETER is available in several models, with standard lengths of 6", 12", 18", 24", 36", or 48" dependent on the rooting depth of the specific crop.
Model SR Features
- 0-100 cb (kPa) range gauge
- Replaceable ceramic tip (white)
- Air-free gauge gives accurate readings
- Large reservoir makes maintenance easy
- Hermetically sealed gauge designed for harsh environments
Part | SR Depth
- 206-AVS-30 | 6’’ (15 cm)
- 212-AVS-30 | 12’’ (30 cm)
- 218-AVS-30 | 18’’ (45 cm)
- 224-AVS-30 | 24’’ (60 cm)
- 236-AVS-30 | 36’’ (90 cm)
- 248-AVS-30 | 48’’ (120 cm)
New And Improved Gauges For 2019
Both SR and LT IRROMETERS now have a membrane vent for better temperature and elevation related compensation, a larger 2 ½ inch face for ease of reading, and a stainless steel rustproof body.
Data Options
Options for connecting IRROMETER tensiometers to data collection or control devices are available, including switching gauges as well as 4-20mA and 0.5V to 4.5V output transducers.