SU1481682A1 - Method of checking a device for determination of density and humidity of soil - Google Patents

Abstract

This invention relates to the field of metrology. The purpose of the invention is to reduce the labor intensity and increase the accuracy of measurements. As samples for calibration, equivalent measures of different density of dry soils are prepared in the form of hollow hermetically sealed cylinders of known mass and specific weight of optic corrosion metals, placed in the vessel of the device, read on the appropriate scale, and the measurement error of the device is determined as the ratio of the difference between indication of the device and the value of the mass equivalent to the volume of the cylinder of the device. 1 tab.

Description

The invention relates to metrology and is used to carry out the calibration of a density meter - N.P. Kovalev used to control the degree of compaction of land structures under field conditions during the construction of automobile roads.

The purpose of the invention is to reduce the labor intensity and increase the accuracy of measurements.

The instrument is calibrated as follows.

To determine the error of measuring the density of dry soil on each of the 5h, ЈP, and 8G scales, equivalent measures of the density of dry stainless steel soils are prepared in the form of hollow, hermetically sealed cylinders in the amount of three pieces per scale.

Thus, nine hollow, hermetically sealed cylinders are prepared, three of them with a volume of 46 cm3 for calibration of the lower part of the scales, three for a volume of 63 cm3 for calibration of the middle part of the scales and three of 80 cm3 for calibration of the upper part of the scales.

The table shows the data according to the parameters of the cylinders corresponding to the parameters of the soil.

To check the scale of $ 4, three cylinders are taken: one with a volume of 46 cm3, the other with a volume of 63 cm3, the third with a volume of 80 cm3

Technical shot is added to each of these cylinders so that the mass of each cylinder with the shot after it is sealed is equal to the density of this cylinder.

t

four

eo

ZE

J Ј 2.60 g / cm

which corresponds to particle density

humus soils,

where P is required mass of the cylinder

with a fraction, g;

V is the volume of this cylinder, cm3. All three cylinders are labeled: a cylinder with a volume of 46 cm3 with letters 4-1 replaces a sample of humus dry soil with a density of 1.20 g / cm3; a cylinder of 63 cm3 in volume 4-2 replaces a sample of humus dry soil with a density of 1.64 g / cm3J a cylinder of 80 cm3 in letters P-3 replaces a sample of humus dry soil with a density of 2.08 g / cm3.

To calibrate the scale of 8 П, similarly, the same three cylinders are prepared each with a density P of 2.65 g / cm3, which corresponds to the density of sandy soil particles, and mark them: a 46-cm3 cylinder with letters P-1 replacing a sample of sandy dry soil with density of 1.22 g / cm3; 63 cm3 cylinder with P-2 letters, replacing a sample of dry sandy soil with a density of 1.67 g / cm3; 80 cm3 cylinder with P-3 letters, replacing a sample of dry sandy soil with a density of 2.12 g / cm3.

For calibration of the scale S G, the same three cylinders are prepared each with a density of J 2.70 g / cm3, which corresponds to the density of clay soil particles, and mark them: a 46-cm3 cylinder with letters G-1 replacing a sample of dry clay soil with a density of 1 , 24 g / cm3, 63 cm3 cylinder with G-2 letters, replacing a clay soil sample with a density of 1.70 g / cm3, 80 cm3 cylinder with G-3 letters, replacing a sample of dry clay soil with a density of 2.16 g / cm3.

The determination of the error in measuring the density of dry soils on any of the three 8H scales, §П and 8Т is made after adjustment of the instrument in the following sequence.

An equivalent measure of the density of the soil, corresponding to the point on the scale under study, is placed in the vessel of the instrument. The vessel is filled with water at 3/4 capacity and inserted into the float nest. A float with a sample (equivalent to the density of the soil) is placed in a bucket of water and the density is determined according to the appropriate scale. At this point

This scale makes three density measurements with a sample instrument (equivalent to the density of the soil).

Of the three definitions, the average density of a dry soil is found. The error in measuring the density of dry soil at the point of interest on this scale is determined as the difference

five

&; hsr m

0

CP

where X is the arithmetic mean value of the density of dry soil determined by the device, g / cm3; O - value of measure equivalent

the density of dry soil for a given point of the scale, about M. -

Me is the mass of equivalent measure, g; Уц, - the volume of the cylinder of the device, cm3. The uncertainty is determined for each scale at the beginning, middle and end of the scale at points corresponding to the value of the equivalent density of dry soils.

All three values of the measurement error of each scale must not exceed the permissible value of the density error of dry soil Ap +0.01 2.20 ± 0.022 g / cm3 or ± 2 divisions of any scale, 8n and §G.

Thus, the proposed method of calibration will reduce the labor costs for checking one instrument and increase the accuracy of determining the accuracy of the instrument being checked.

Claims (1)

Invention Formula The method of calibration of the device to determine; dividing the density and moisture of the soil, including preparing samples of various known densities, placing them in the vessel of the instrument, determining the density of dry soil using the appropriate scale of the instrument and determining the measurement error of the instrument, characterized in that, in order to reduce labor intensity and increase the accuracy of measurements, as samples Equivalent measures are prepared for different densities of dry soils in the form of hollow hermetically sealed cylinders of known mass and specific gravity of anti-corrosion metals, which are placed in the tank 514816826 instrument and take readings according to the relation between the instrument readings and the corresponding scale, and the error by measuring the mass of the equivalent measure, the units are determined as being divided by the cylinder volume of the instrument. Editor A. Kozoriz Compiled by G. Martynov Tehred M. Didyk Proofreader L. Pilipenko Order 2682/46 Circulation 790 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 Production and Publishing Combine Patent ,, Uzhgorod, st. Gagarin, 101 Subscription