Mechanical tensiometer for low water tension (light soil, sandy, shrubs, etc.)

The mechanical tensiometer is made up of a plastic tube with a transparent part in its upper segment, whereas a porous ceramic dome is connected to its bottom end. Into its uppermost end is screwed a mechanical vacuum meter in the shape of a watch with a hand.

In the standard tensiometer of Ami Tens, the vacuum meter has a ¼” thread in the back which screws into a plastic adaptor within which there is a special seal that prevents the vacuum from leaking out of the apparatus. In order to fill in or add water, it is necessary to manually remove the vacuum meter and to close using force at the end of the procedure. The ceramic is inserted into the area of the roots whereas its outside is in close contact with the soil and its inside is in contact with the water in the tube. The dryer is the soil, the greater will be the tension of the water (sub-pressure) inside the tube and we read the data. The vacuum meter indicates the tension in units of negative pressure, that is, millibars in the following values: 0 -- for saturated soil, up to 250 -- for totally dry soil. After irrigating or rain, the tension of the water will decrease. By following up continuously, the farmer can decide when and how much to irrigate in the most efficient manner.

All what you have to choose is the depth of the tensiometer in order for the ceramic at the bottom (middle of the ceramic) to be at the uppermost level of the roots of the plant, or the middle part of the roots, or the deepest level of the roots. It is desirable to place at least 2 tensiometers at different depths in order to obtain data that will allow to decide on the timing and the amount of the irrigation. As a standard, we provide tensiometers at depths of 20, 30 and 40 cm. The pipes are made of PVC with an outer diameter of 20 mm. The length indicated is not the physical length of the pipe, but instead the pipe that is appropriate to be placed at the desired depth. We provide a label indicating the depth, whereas the label is at the level of the surface of the soil.

1. You have to read the directives regarding the location and the use of the data in the Chapter on tensiometers in general. It is important to indicate that when using a mechanical tensiometer it is important to visit on a daily basis and to record continuously, manually, in order to discern changes and tendencies that occur continuously in the soil. It is recommended to always measure at the same hours. It is important to mark the tensiometer in a way that stands out and to protect it from getting broken accidentally.
2. It is also possible to provide vacuum meters having different characteristics, such as: lateral threading or measurement scope of 0-60 centibars, depths that are different from the standard and the like. in order to receive an offer for a product with a unique characteristic, you have to submit a request to the Company and we will make an offer accordingly.