Easy Test

SOIL WATER, SALINITY AND OXYGENATION STATUS MONITORING DEVICES

from 

INSTITUTE of AGROPHYSICS, POLISH ACADEMY of SCIENCES

The following measuring devices are intended for the determination of:

- water content by means of Time-Domain Reflectometry (TDR)
  method,
- salinity (bulk electrical conductivity) of soils by means of TDR,
- temperature of the soil,
- soil water capillary pressure (suction force),
- redox potential of platinum electrode in the soil.

The TDR-based solutions are worldwide patented. There are three types of meters available:

Field Operated Meter (FOM)
Field Operated Data LOGger (D-LOG)
Laboratory Operated Meter (LOM)

Also adequate kinds of probes are offered: Field Probe (FP) and Laboratory Probe (LP) respectively.

FOM is hand-held, battery operated, microprocessor controlled device designed for in situ field measurements of soil moisture, temperature and salinity. It is particularly suitable for periodic measurements at random and/or fixed locations, where water content, temperature and salinity distribution is to be determined by readings taken at various levels of the soil profile. 

FP is a probe for momentary or for semipermanent installation. Through a preaugered pilot hole it can reach any depth down to 4 m without destroying either the soil structure or disturbing the heat and mass transport in the soil. It can be left then intact for as long period of time as needed.

A single probe may also be used for momentary measurements in shallow layers of the soil profile by walking over the field and inserting the probe in chosen sites.

For semipermanent installation, when deeper layers are to be monitored, several FPs can be inserted from the soil surface or horizontally through a side wall of a soil pit. A probe installed once may be left intact in the soil for as long as necessary and then drawn out at the end of the experiment.

FOM/mts - field operated meter for simultaneous measurements of the soil moisture, temperature and salinity (bulk electrical conductivity). FOM/mts is provided with a 160 by 128 dot matrix graphic LCD to display data and TDR trace simultaneously. Also adequate probes are offered:

FP/m - field probe for measurements of soil moisture,

FP/mts - field probe for simultaneous measurements of soil moisture, temperature and salinity.

LOM is an IBM PC compatible aided device working under control of a special software. It has been designated mainly to control long term laboratory experiments which require monitoring of water, salt and heat transport by means of periodic recording of instantaneous soil moisture, capillary tension, temperature and electrical conductivity profiles in chosen time intervals. To read moisture a factory installed conversion equation for mineral or organic soils can be chosen and/or user determined calibration functions can be applied as well.

To switch between probes LOM is provided with up to 16 single-pole-8-throw multiplexers. This makes it possible to switch between up to 128 LP/ms, LP/t and LP/p probes.

LOM works with the following probes:

LP/ms - Laboratory miniProbes designed for recording instantaneous profiles of moisture and salinity in soil columns or in undisturbed soil cores
UP/ms - User-made Probes for moisture and salinity measurement
LP/p - Laboratory Probes (minitensiometers) for measurements of soil water capillary pressure (suction force, matric potential)
LP/t - Laboratory Probes for temperature measurement

Several LP-probes of a selected kind or of all types can be inserted through the wall of a soil column or a steel sampling cylinder, thus allowing for vertical scanning of the instantaneous moisture, capillary tension (matric potential, suction force), temperature and electrical conductivity profiles. This makes it possible to collect a set of corresponding water content, water potential, electric conductivity and temperature data from drying or wetting front transition, from which, after further processing, one can obtain complete set of unsaturated water flow characteristics of the soil i.e.: water retention (PF) curve, unsaturated water conductivity (k-function), differential water capacity and unsaturated water diffusivity as well as solute transport data. Also heat transport coefficients (as the thermal conductivity, thermal diffusivity, specific heat) can be determined if a heat flux meter is installed in an experimental column.

D-LOG/mpts - is a moisture/capillary pressure/temperature/salinity datalogger for field application that is able to switch between up to 128 probes type of FP/mts (or FP/m) and up to 128 tensiometers.

EasyTest
ul. Doświadczalna 4
20-290 Lublin, Poland
e-mail: easytest@ipan.lublin.pl
tel.: +48817445061
fax.: +48817445067
EasyTest is a part of the Institute of Agrophysics, Polish Academy of Sciences