Agricultural sampling system and related methods

Patent metadata

Field	Value
Publication number	US-12031996-B2
Application number	US-202117144107-A
Country	US
Kind code	B2
Filing date	Jan 7, 2021
Priority date	Jul 10, 2018
Publication date	Jul 9, 2024
Grant date	Jul 9, 2024

Abstract

An automated computer-controlled sampling system and related methods for collecting, processing, and analyzing agricultural samples for various chemical properties such as plant available nutrients. The sampling system allows multiple samples to be processed and analyzed for different analytes or chemical properties in a simultaneous concurrent or semi-concurrent manner. Advantageously, the system can process soil samples in the “as collected” condition without drying or grinding. The system generally includes a sample preparation sub-system which receives soil samples collected by a probe collection sub-system and produces a slurry (i.e. mixture of soil, vegetation, and/or manure and water), and a chemical analysis sub-system which processes the prepared slurry samples for quantifying multiple analytes and/or chemical properties of the sample. The sample preparation and chemical analysis sub-systems can be used to analyze soil, vegetation, and/or manure samples.

First claim

The invention claimed is:

1. A system for determining a volume of a collected sample, the system comprising:
a mixing device defining a mixing chamber of known fixed volume having an inlet;
the mixing device comprising a rotatable motor-driven blade assembly disposed in the mixing chamber;
an actuated sample loading valve fluidly coupled to the inlet for introducing a sample into the mixing chamber;
a solvent pump fluidly coupled to the mixing chamber and operable to pump a solvent into the mixing chamber to prepare a slurry from the sample comprising solid particles;
a first temperature sensor operable to measure a temperature of the slurry in the chamber;
a reference container of known fixed volume fluidly coupled to the mixing chamber by a flow conduit controlled by a gas valve;
a pressurized gas source fluidly coupled to the reference container to fill the reference container with gas;
an actuated slur outlet valve fluidly coupled to a slurry outlet from the chamber; and
a pressure sensor operable to measure a pressure of the gas in the reference container;
a second temperature sensor operable to measure a temperature of the gas in the reference container;
a reference slurry outlet valve fluidly coupled to the chamber;
a weighing device fluidly coupled to the reference slurry outlet valve, the weighing device configured and operable to receive and measure a weight of at least a portion of slurry extracted from the mixing chamber;
a programmable controller operably and communicably coupled to the mixing device, the slurry outlet valve, the reference slurry outlet valve, the solvent pump, the weighing device, the temperature sensors, and the pressure sensor, the controller being configured to:
obtain the weight of the at least a portion of slurry from the weighing device;
determine a volume of slurry in the mixing chamber based at least in part on the pressure and temperature of the gas measured in the reference container and the temperature of the slurry in the mixing chamber;
determine an initial solvent to sample ratio of the at least a portion of slurry based on using the weight of the at least a portion of slurry; and
compare the initial solvent to sample ratio to a target solvent to sample ratio preprogrammed into the controller.

2. The system according to claim 1 , wherein the controller is further configured to:
open the agricultural sample loading valve to add the agricultural sample to the mixing chamber;
operate the solvent pump to add solvent to the mixing chamber;
operate the blade assembly to prepare the slurry;
open the reference slurry outlet valve so that the at least a portion of the slurry flows into the weighing device.

3. The system according to claim 2 , wherein the controller is further configured to add additional solvent to the slurry in the mixing chamber in accordance with a preprogrammed target solvent to agricultural sample ratio, and operate the blade assembly to remix the additional solvent and slurry.

4. The system according to claim 3 , wherein the controller is further configured to open the slurry outlet valve to transfer the remixed slurry to an analysis system to measure an analyte in the remixed slurry.

5. The system according to claim 4 , wherein the weighing device is a weigh coil.

6. The system according to claim 5 , wherein the weigh coil includes a strain gauge operable to measure the weight of the reference slurry.

7. The system according to claim 5 , further comprising a movable excitation plunger which acts on a target surface integrally formed with or rigidly attached to the weigh coil, and an electronic vibration sensor located proximate to the target surface, the plunger operable to strike the target surface inducing a vibration in the weigh coil generating a frequency response measured by the sensor to determine the weight of the reference slurry.

8. The system according to claim 5 , further comprising an emitting piezo transducer mounted on one end of the weigh coil and excited at a specified predetermined frequency to induce vibration in the weigh coil, and a separate receiving piezo transducer mounted on the opposite end of the weigh coil which measures a response of the weigh coil to the induced frequency for determining the weight of the reference slurry.

9. The system according to claim 5 , further comprising an electronic vibration sensor located proximate to the weigh coil, the electronic vibration sensor generating a frequency response measured by the sensor to determine the weight of the reference slurry, wherein system operation generates an excitation.

10. A method for preparing an agricultural sample slurry controlled by a programmable controller, the controller performing steps comprising:
adding an amount of agricultural sample to a mixing chamber of a mixer fluidly coupled to a reference container containing a gas through an isolation valve;
adding a known volume of solvent to a mixing chamber of a mixer;
mixing the solvent and agricultural sample to prepare a slurry;
extracting at least a portion of slurry from the mixing chamber;
transferring the at least a portion of slurry to a weighing device;
obtaining a weight of the at least a portion of slurry using the weighing device;
determining a volume of slurry in the mixing chamber based at least in part on a pressure and temperature of the gas measured in the reference container and a temperature of the slurry in the mixing chamber;
determining an initial solvent to agricultural sample ratio of the at least a portion of slurry based on using the weight of the at least a portion of slurry;
comparing the initial solvent to agricultural sample ratio to a target solvent to agricultural sample ratio preprogrammed into the controller.

11. The method according to claim 10 , further comprising after the comparing step:
adding an additional volume of solvent to the mixing chamber to obtain the target solvent to agricultural sample ratio of the slurry; and
mixing the slurry with additional volume of solvent with the blade assembly.

12. The method according to claim 11 , further comprising after the step of adding the agricultural sample, estimating a volume of the agricultural sample by volumizing.

13. The method according to claim 10 , wherein the controller determines the volume of slurry in the mixing chamber via employing the Ideal Gas Law.

14. The method according to claim 10 , further comprising the controller performing steps of:
fluidly isolating the reference container from the mixing chamber;
measuring a first gas pressure in the reference container;
fluidly connecting the reference container to the mixing container;
pressurizing the slurry in the mixing chamber via flowing the gas into the mixing chamber;
measuring a second gas pressure in the reference container;
wherein the step of determining the volume of slurry in the mixing chamber uses the first and second gas pressures;
determining an initial solvent to agricultural sample ratio of the at east a portion of slurry.

15. The method according to claim 14 , further comprising measuring a temperature of the gas in the reference container before pressurizing the slurry in the mixing chamber, wherein the step of determining the volume of slurry in the mixing chamber uses the gas temperature.

16. The method according to claim 14 , wherein the step of determining the volume of slurry in the mixing chamber further comprises measuring a temperature of the slurry in the mixing chamber, wherein the step of determining the volume of slurry in the mixing chamber uses the slurry temper

Assignees

• Prec Planting Llc

Inventors

• Swanson Todd
• Koch Dale
• Levy Kent
• O'Neall Matthew
• Harman Reid
• Schaefer Timothy
• Vaccari Adam

Classifications

• G01N35/1072

  with provision for selective pipetting of individual channels · CPC title

• G01N35/08

  using a stream of discrete samples flowing along a tube system, e.g. flow injection analysis · CPC title

• G01N2001/4061

  Solvent extraction · CPC title

• G01N1/4055

  by solubility techniques · CPC title

• G01N1/04

  in the solid state, e.g. by cutting · CPC title