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YI. CORRECTIONS FOR VARYING SOILS <br />Density <br />The 3400 Series is calibrated for soils, aggregates, concrete, and <br />asphalt with a density range of 1100 to 210D kg/m3 (70 to 170 pCF). <br />Corrections to the density calibrations are necessary in rare condi- <br />tions such as work involving industrial waste, mine ta111ngs and <br />coal. Far a general discussion of calibration, see Section I%-I. If <br />working with coal, see Section VII-E. For other appl icatlons, con- <br />tact a factory representative. <br />Moisture <br />The 3400 Series measures moisture by determining Che hydrogen (H) <br />content of the soil antl relating this to water (H20) content. In <br />some so115 [here are campoun ds other than water which contain hytlro- <br />gen. Also, there are elements in some soils which absorb neutrons, <br />lowering count rate. The 3400 is cai ib rated for soils without neu- <br />tron absorbing elements or components other Chan ester containing hy- <br />drogen; and need not be ad,j usted for most soils. <br />To detenmine a correct ion factor. oroceed as follows: <br />1. Take flue or more oven dry antl gauge sample pairs. Be sure oven <br />dry samples are at least f000-2000 grams taken under the center of <br />the gauge Co a depth of 15-20 cm or fi-8 inches. Be sure nuclear <br />tests are taken with the Moisture Correction set at BB on the 3418 <br />scaler. <br />2. prepare a Chart as shown in the chart below. <br />Sample No. SM Oren Ory SM Gauge SOven Ory - S Gauge <br />1 4.5 B.6 -4.1 <br />2 4.0 5.8 -1.8 <br />3 7.2 9.7 -2.5 <br />4 6.7 8.6 -1.9 <br />5 5.1 7.3 -2.2 <br />Avera a 5.5 8.0 -2.5 <br />The difference between the oven dry and the gauge is espectetl to <br />vary from sample to sample due to normal variation. If the differ- <br />ence indicates the gauge is sometimes higher and sometimes lower <br />than the oven dry no correction may be needed. If the differ- <br />ence indicates the gauge reads consistently higher or lower than <br />the oven dry, a correction factor 1s needed. To determine the <br />correction factor, calculate the average value and proceed as <br />follows. <br />FOR THE 34118 <br />Calculate the correction factor using the average value, as follows: <br />Correction Factor = x M Oven Ory - i M Gauge a 1000 <br />100 i i M Gauge <br />- 12 - <br />