The Model R is the standard one-piece Irrometer for general use with irrigated row, tree, and field crops, but can also be used in greenhouse and nursery applications or for monitoring Vadoze Zones. Simply make a hole and insert the tensionometer into the soil, fill it with distilled water and prime the suction with the Vacuum Hand Pump (Model R Irrometer Service Kit). After about 24 hours, the ceramic block will reach equilibrium with the soil and give the moisture level. Leave it installed in the soil and you can periodically check to see when your crops or trees need additional irrigation.

Features a tough Butyrate plastic body that is impervious to soil chemicals or electrolysis, a fixed porous ceramic tip designed to give quick response to variations in soil moisture, and a hermetically sealed gauge that indicates soil suction from 0 to 100 centibars (gauge operates counter-clockwise). A large reservoir with a screw cap for filling holds a reserve supply of water to replace water lost by action of drying soil.

Partial unscrewing of cap releases air, and refills the tube from the reservoir. All joints are permanently sealed. Irrometer fluid, supplied with the Service Unit Accessory, adds color to the water for easy water level observation. The Model R Irrometer requires the Service Unit Accessory and the Soil Coring Tool with the initial order.