工程用土壤測試方法方法5.8.1概述

1、AS 1289.5.8.1-2007Australian Standard®澳大利亞標(biāo)準(zhǔn)Methods of testing soils for engineering purposes工程建設(shè)項(xiàng)目測試土壤的方法Method 5.8.1: Soil compaction and density testsDetermination of field density and field moisture content of a soil using a nuclear surface moistureDensity gaugeDirect transmission mode方法5.8

2、.1: 土壤壓實(shí)和密度測試使用核表面濕度密度測量計(jì)確定土壤的場密度和場含水量直接傳輸模式1 SCOPE范圍This Standard sets out the method for determining the field density of a soil using a nuclear surface moisture-density gauge in the direct transmission mode of operation. It describes the method for determining the field moisture content of a soil

3、 using the same device, but other methods of moisture content determination may also be used. Gauges determine the gross mass per unit volume (field wet density) of the soil and the mass of water per unit volume (field water content) of the soil. Field dry density and moisture content can be calcula

4、ted from these values.本標(biāo)準(zhǔn)為以直接傳輸?shù)倪\(yùn)作模式使用核表面濕密度測量計(jì)確定土壤的場密度制定了方法。它描述了使用同一種裝置確定土壤場含水量的方法，但是也有可能用到其他確定含水量的方法。測量計(jì)確定了土壤每單位體積的總質(zhì)量（場濕密度）和土壤每單位體積的水的質(zhì)量（場含水量）。場干密度和含水量可以從這些值中計(jì)算出來。This method is applicable to soils having not more than 20% by mass of particles retained on the 37.5 mm sieve. Some soils containing

5、variable percentages of chemically bound water or other neutron moderators or absorbers may require the moisture content of the material to be determined in accordance with AS 1289.2.1.1 or one of the subsidiary methods, AS 1289.2.1.2, AS 1289.2.1.4, AS 1289.2.1.5 or AS 1289.2.1.6.本方法適用于所包含的保留在37.5

6、mm篩上的微粒質(zhì)量不超過20%的土壤。一些包含可變比例的化合水或其他中子慢化劑或吸收劑的土壤可能需要根據(jù)AS 1289.2.1.1或輔助方法之一，如AS 1289.2.1.2, AS 1289.2.1.4, AS 1289.2.1.5 或 AS 1289.2.1.6確定材料的含水量。Because of the variety of gauges available, this method does not detail the operation of the gauge but refers the operator to the manufacturers handbook.由于有多種

7、測量計(jì)，所以本方法沒有詳細(xì)說明測量計(jì)的使用，而是讓操作員參照制造商手冊。When nuclear gauges are used for density or moisture measurement, the volume of material being assessed is not precisely known; however, reference to the manufacturers handbook and current literature may indicate the likely volume. The zone of influence for the nu

8、clear moisture function of a gauge is normally restricted to less than 150 mm below the base of the gauge.當(dāng)使用核測量計(jì)測量密度或濕度時，并不知道所評估材料的精確體積；然而，參考制造商手冊和現(xiàn)有的文獻(xiàn)也許會指示可能的體積。一個測量計(jì)的核濕度功能的影響區(qū)域一般都限定在測量計(jì)底部以下150 mm以內(nèi)的地方。A nuclear gauge gives an indirect measure of field density and field moisture content and hence

9、 requires calibration in accordance with AS 1289.5.8.4. Regular checks on the operation and the calibration of the gauge are also required (see Clause 5). When the moisture content is measured using the gauge, the intercept of the moisture calibration equation needs to be determined for each materia

10、l being tested. 一個核測量計(jì)間接地測量了場密度和場含水量，因此它需要根據(jù)AS 1289.5.8.4進(jìn)行標(biāo)定。同樣需要對測量計(jì)的操作和標(biāo)定進(jìn)行定期的檢查（見第5條）。當(dāng)使用測量計(jì)測量含水量時，濕度標(biāo)定等式的截距需要依每次測試的材料而定。2 REFERENCED DOCUMENTS參考文件The following documents are referred to in this Standard:本標(biāo)準(zhǔn)中參考了以下文件：AS1289Methods of testing soils for engineering purposes1289 工程建設(shè)項(xiàng)目測試土壤的方法1289.2.

11、1.1Method 2.1.1:Soil moisture content testsDetermination of the moisture content of a soilOven drying method (standard method)1289.2.1.1 方法2.1.1：土壤含水量測試土壤含水量的確定烘干法（標(biāo)準(zhǔn)方法）1289.2.1.2Method 2.1.2:Soil moisture content testsDetermination of the moisture content of a soilSand bath method (subsidiary metho

12、d)1289.2.1.2 方法2.1.2：土壤含水量測試土壤含水量的確定砂浴法（輔助方法）1289.2.1.4 Method 2.1.4: Soil moisture content testsDetermination of the moisture content of a soilMicrowave-oven drying method (subsidiary method)1289.2.1.4 方法2.1.4：土壤含水量測試土壤含水量的確定微波烘干法（輔助方法）1289.2.1.5Method 2.1.5:Soil moisture content testsDetermination

13、 of the moisture content of a soilInfrared lights method (subsidiary method)1289.2.1.5 方法2.1.5: 土壤含水量測試土壤含水量的確定紅外線方法（輔助方法）1289.2.1.6Method 2.1.6:Soil moisture content testsDetermination of the moisture content of a soilHotplate drying method1289.2.1.6 方法2.1.6: 土壤含水量測試土壤含水量的確定熱板烘干法1289.2.3.1Method 2.

14、3.1:SoilmoisturecontenttestsEstablishmentof correlationSubsidiary method and the standard method (AS 1289.2.1.1)1289.2.3.1 方法2.3.1: 土壤含水量測試關(guān)聯(lián)性的建立輔助方法和標(biāo)準(zhǔn)方法(AS 1289.2.1.1)1289.5.4.1Method 5.4.1:Soil compaction and density testsCompaction control testDry density ratio, moisture variation and moisture r

15、atio1289.5.4.1 方法5.4.1: 土壤壓實(shí)度和密度測試壓實(shí)度控制測試干密度比例，濕度變化和濕度比例1289.5.4.2 Method 5.4.2:Soil compaction and density testsCompaction control testAssignment of maximum dry density and optimum moisture content values1289.5.4.2 方法5.4.2: 土壤壓實(shí)和密度測試壓實(shí)度控制測試最大干密度和最佳含水量值的指定1289.5.8.4Method 5.8.4:Soil compaction and d

16、ensity testsNuclear surface moisture-density gaugesCalibration using standard blocks1289.5.8.4 方法5.8.4: 土壤壓實(shí)和密度測試核表面濕密度測量計(jì)使用標(biāo)準(zhǔn)塊進(jìn)行標(biāo)定3 SAFETY PRECAUTIONS安全防范The equipment used in this method utilizes radioactive materials, which may be hazardous to health unless proper precautions are taken. Therefore

17、, it is essential that operators receive instruction on potential hazards and precautions, together with routine safety check procedures such as the use of personal radiation monitors, source leak testing and use of radiation survey meters. Statutory regulations cover the use, transport and storage

18、of radioactive substances in the State or Territory in which the gauge is to be used.本方法中使用的儀器運(yùn)用了放射性材料，除非采取了合適的防范措施，否則會給健康帶來危害。因此，至關(guān)重要的一點(diǎn)是操作員得到有關(guān)潛在危害和防范措施方面的指示，同時進(jìn)行常規(guī)的安全檢查程序，比如使用個人放射監(jiān)測器，源泄漏測試和使用放射調(diào)查表等。法定規(guī)則涵蓋了放射性物質(zhì)在使用測量計(jì)的國家或領(lǐng)土內(nèi)的使用，運(yùn)輸和儲存。4 APPARATUS儀器The following items of apparatus are essential for

19、the correct performance of the test(additional items may be required for the correct usage of a particular model of gauge):以下儀器對進(jìn)行正確的測試至關(guān)重要（在正確使用某一類型測量計(jì)時可能需要額外的儀器）：(a) Nuclear surface moisture-density gauge calibrated in accordance with AS 1289.5.8.4, logbook, manufacturers handbook for the gauge, a

20、nd the manufacturers reference block for standard counts that were used for the calibration of the gauge.核表面濕度密度測量計(jì)，根據(jù)AS 1289.5.8.4，日志本，測量計(jì)制造商手冊和制造商用于測量計(jì)標(biāo)定的標(biāo)準(zhǔn)計(jì)數(shù)參考塊進(jìn)行標(biāo)定。The maximum uncertainty of the predicted density of the nuclear gauge, at the 95% confidence limits, for the calibration equation fo

21、r the depth being used for the test shall not exceed 0.06 t/m3. The maximum uncertainty of the predicted water content, at the 95% confidence limits, from the calibration equation (as defined in AS 1289.5.8.4) shall not exceed 0.07 t/m3.在測試中所使用深度的標(biāo)定等式的95%的置信極限內(nèi)，核測量計(jì)的所預(yù)測密度的最大不確定性不得超過0.06 t/m3。在標(biāo)定等式（見

22、AS 1289.5.8.4中的定義）的95%的置信極限內(nèi)，所預(yù)測含水量的最大不確定性不得超過0.07 t/m3。(b) Scraper plate, shovel and brush.刮板，鏟子和刷子。(c) Rotary hammer drill or drill rod capable of forming a hole at least 16 mm in diameter.能夠形成直徑至少為16 mm的孔的回轉(zhuǎn)式錘鉆或鉆桿。NOTE: In order to reduce distortion of the surface of the compacted soil, the shaft

23、 of the drill rod may be tapered 1 in 100 over its length.注：為了減少壓實(shí)土壤表面的變形，鉆桿的軸可與其長度形成1的錐角。(d) Secondary block of naturally occurring stone or concrete of minimum size 500 mm long by 300 mm wide by at least 50 mm greater than the greatest depth at which the gauge density system consistency checks wil

24、l be carried out, or a standard density block as defined in AS 1289.5.8.4.天然形成的石頭或混凝土的二次塊，長至少為500 mm，寬為300 mm，深度應(yīng)至少比執(zhí)行測量計(jì)密度系統(tǒng)的一致性檢查時的最大深度還要大50 mm，或者AS 1289.5.8.4中所定義的標(biāo)準(zhǔn)密度塊。NOTE: Concrete secondary blocks may be used provided they have been allowed to dry to a stable state following manufacture, and

25、are kept in a stable moisture condition.注：混凝土二次塊可以使用，條件是它們在產(chǎn)出之后已經(jīng)被烘干至一種穩(wěn)定的狀態(tài)，并保存于一種穩(wěn)定的濕潤環(huán)境中。(e) A fine density sand of one size (passing 0.600 µm) of the material under test.所測試材料中尺寸一致的細(xì)密度砂土（通過0.600 µm）。5 GAUGE CALIBRATION AND OPERATIONAL CHECKS測量計(jì)的標(biāo)定和運(yùn)行檢查Nuclear surface moisture-density g

26、auges shall be calibrated at each probe position of interest in accordance with AS 1289.5.8.4 and shall be recalibrated at least once every two years or after any major repair or component replacement. Regular checks on the operation and calibration of the gauges shall be made as follows:核表面濕度密度測量計(jì)應(yīng)

27、該依據(jù)AS 1289.5.8.4在每個相關(guān)的探針位置進(jìn)行標(biāo)定，并且每隔兩年應(yīng)至少重新進(jìn)行一次標(biāo)定或在任何大修或零部件更換之后重新進(jìn)行標(biāo)定。應(yīng)定期對測量計(jì)的運(yùn)行和標(biāo)定進(jìn)行檢查，程序如下：(a) Standard count checks, as detailed in Paragraph A1 of Appendix A, shall be made on each day of use.在使用的每一天都應(yīng)當(dāng)進(jìn)行標(biāo)準(zhǔn)計(jì)數(shù)檢查，詳見附錄A的A1段。(b) Gauge function checks, as detailed in Paragraph A2 of Appendix A, shall

28、be made at least once per month.每個月至少執(zhí)行一次測量計(jì)功能檢查，詳見附錄A的A2段。(c) Density system consistency checks, as detailed in Paragraph A3 of Appendix A, shall be made at least once per month.每個月至少進(jìn)行一次密度系統(tǒng)一致性的檢查，詳見附錄A的A3段。(d) Moisture intercepts for each material shall be determined as detailed in Appendix B and

29、 redetermined應(yīng)確定每種材料的濕度截距，詳見附錄B，并在以下情況下對其進(jìn)行重新確定(i) if the time between the use of the value and the determination of the value is greater than three months; or如果使用此值和確定此值之間的時間間隔超過了三個月；或者(ii) if the maximum dry density as determined in accordance with AS 1289.5.4.2 has been reassigned.如果根據(jù)AS 1289.5.4

30、.2確定出的最大干密度已經(jīng)改變。6 PROCEDURE程序The procedure shall be as follows:程序應(yīng)當(dāng)如下：(a) At the works site, obtain and record the field standard counts, with the manufacturers reference block placed on the material to be tested, in accordance with the procedure specified for the gauge by the manufacturer. The fiel

31、d standard counts are valid for testing of material on which they were determined, for that test lot only.在工作場點(diǎn)，將制造商的參考塊放置于待測試的材料之上，根據(jù)制造商為測量計(jì)指定的程序獲取場標(biāo)準(zhǔn)計(jì)數(shù)并作下記錄。場標(biāo)準(zhǔn)計(jì)數(shù)對與之對應(yīng)材料的測試有效，但僅僅只對此測試場點(diǎn)有效。NOTE: The gauge should not be used near any vertical projection that is within 150 mm of the short side of the

32、 gauge and 600 mm of the long side of the gauge. When a gauge is used within these distances, the effects of reflected radiation has to be taken account of by performing a separate field standard count for each density and moisture count. When used in a trench, the gauge should be placed in the tren

33、ch so that the longitudinal axis of the gauge is parallel to the structure or the walls of the trench. If the material to be tested is overlying a pipe, the end of the probe should be at least 50 mm above the pipe.注：如果在測量計(jì)的短側(cè)邊150 mm和長側(cè)邊600 mm以內(nèi)有垂直的凸出物，那么測量計(jì)不得在其附近使用。當(dāng)在這種距離以內(nèi)使用了測量計(jì)，那么必須考慮到發(fā)射輻射的效應(yīng)，對每個密

34、度和濕度計(jì)數(shù)執(zhí)行單獨(dú)的場標(biāo)準(zhǔn)計(jì)數(shù)。當(dāng)在溝中使用測量計(jì)時，應(yīng)當(dāng)在測量計(jì)放在溝中，使得測量計(jì)的縱軸與溝的結(jié)構(gòu)或壁平行。如果待測試的材料覆蓋于管道上，那么探針的末端應(yīng)當(dāng)至少在管道以上50 mm。(b) Select a test site on which density and moisture contents are to be determined and ensure that選擇一個其密度和含水量待定的測試地點(diǎn)，并確保(i) loose material is swept or cleared off the surface; and其表面的松散材料已被掃除或清除；并且(ii) the

35、surface is essentially flat and essentially free of cracks and depressions.其表面十分平坦，基本沒有裂痕和凹陷。NOTE: Cracking in the surface of the soil should not adversely affect the test results provided the gauge is so positioned that no crack extends from the source directly to the detector tubes and provided th

36、e soil integrity has not been affected.注：如果測量計(jì)的位置使得沒有裂痕從源直接延伸至監(jiān)測管，并且土壤的完整性沒有受到影響，那么土壤表面的裂痕就不會給測試結(jié)果帶來負(fù)面影響。(c) Using the scraper plate as a guide, drill or drive a direct transmission access hole to a depth at least 25 mm greater than the required test depth.用刮板作為引導(dǎo)，鉆出或推出一個直接傳輸通道孔，深度應(yīng)至少比所需測試深度大25 mm。N

37、OTES:注：1 When testing a layer(s) of soil, the required test depth is the maximum depth that allows both the probe to be located in the testing position and the probe to remain in the layer(s) being tested.在測試土壤層時，所需的測試深度為既使得探針置于測試的位置又使得探針能保留在待測試層中的最大深度。2 The surface of the compacted soil should be f

38、lat after the removal of the drill rod.在撤除鉆桿之后壓實(shí)土壤的表面應(yīng)保持平坦。(d) Place the gauge on the test site, checking that it is firmly seated. It is permissible to use small quantities of fines of the material under test or a fine sand to fill small surface voids, taking care to avoid placing fines in the hole

39、. This material shall not form an added layer.將測量計(jì)置于測試地點(diǎn)，檢查它是否穩(wěn)固地站立。允許使用測試材料中少量的細(xì)粒或細(xì)砂去填補(bǔ)表面的小孔穴，注意不要將細(xì)粒放到孔中。這些材料不能形成另外一層。(e) Insert the probe into the hole to the required test depth. Move the gauge longitudinally so that the side of the probe nearest to the density detector is in contact with the si

40、de of the hole.將探針插入孔中所需的測試深度?？v向移動測量計(jì)使得緊挨密度探測器的探針的側(cè)邊與孔的側(cè)邊接觸。(f) Follow the gauge manufacturers instructions to obtain at least one density reading with a count time of not less than 60 s. Record the field wet density (), and the corresponding density count.按照測量計(jì)制造商的指示，至少獲取一次密度讀取值，計(jì)數(shù)時間不得少于60 s。記錄下場濕密

41、度()和相應(yīng)的密度計(jì)數(shù)。If the moisture content of the soil is to be determined using the gauge, follow the gauge manufacturers instructions to obtain at least one moisture reading with a count time of not less than 60 s. Record field water content of the soil (W) or field moisture content of the soil (w) and t

42、he corresponding moisture count.如果土壤的含水量將通過測量計(jì)確定出，那么按照測量計(jì)制造商的指示，至少獲取一次密度讀取值，計(jì)數(shù)時間不得少于60 s。記錄下土壤的場含水量(W)或土壤的場含水量(w)以及相應(yīng)的濕度計(jì)數(shù)。NOTES:注：1 When using gauges with in-built data processing circuitry that enables direct reading of density and moisture content, it is important for traceability to record the c

43、ounts as well as the direct readings from the gauge for each set of readings.當(dāng)使用的測量計(jì)中裝有能夠直接讀取密度和含水量的存入信息處理電路時，重要的一點(diǎn)是可跟蹤性能夠從測量計(jì)中為每個讀取值集合記錄下計(jì)數(shù)和直接讀取值。2 Gauge calibration data may be in the form of calibration constants stored in the gauge microprocessor, calibration constants to be used in association

44、with an electronic calculator, calibration charts or count ratio versus density tables.測量計(jì)的標(biāo)定數(shù)據(jù)可能是測量計(jì)微處理器中所儲存的標(biāo)定常量，標(biāo)定常量將與電子計(jì)算器，標(biāo)定圖表或計(jì)數(shù)比例密度表格聯(lián)合使用。3 Some gauges are not fitted with a microprocessor, while other gauges may be fitted with a microprocessor but require the use of a different and incompati

45、ble form of calibration equation than that supplied by the manufacturer. Such gauges require recording of the counts only.有些測量計(jì)沒有裝有微處理器，而其他測量計(jì)可能裝有微處理器但是需要使用與制造商提供的標(biāo)定等式不同且不兼容形式的標(biāo)定等式。這樣的測量計(jì)只需要計(jì)數(shù)的讀取值。4 Nuclear surface moisture-density gauges determine field moisture content using backscatter and field

46、density using direct transmission. Therefore, the volume of material being assessed when measuring field density can differ from that to which moisture measurements apply.核表面濕度密度測量計(jì)使用背向散射確定場含水量，使用直接傳輸確定場密度。因此，在測量場密度時，待評估的材料體積會與測量濕度時不同。5 Some gauge models make an in-built correction to wet density to

47、 take into account the effect of gamma mass attenuation of water. Users should satisfy themselves that this correction does not significantly affect the accuracy of the wet density reading.有些測量計(jì)模型會考慮到伽瑪對水質(zhì)量衰減的影響從而對濕密度進(jìn)行內(nèi)部校正。用戶應(yīng)當(dāng)注意這種校正不會給濕密度讀取值的準(zhǔn)確性帶來很大的影響。(g) If the moisture content of the soil is to

48、 be determined using a method other than the gauge, remove any fines or fine sand placed on the surface and obtain a sample of soil from the test site by excavating a hole with vertical sides to the depth at which the probe was located during the tests. The centre of the hole shall be at the centre

49、of the gauge base. Determine the moisture content of the soil in accordance with AS 1289.2.1.1, AS 1289.2.1.2, AS 1289.2.1.4, AS 1289.2.1.5, or AS 1289.2.1.6.如果土壤的含水量是通過使用測量計(jì)以外的方法確定的，那么須清除土壤表面上的任何細(xì)?；蚣?xì)砂，并在測試地點(diǎn)挖掘一個側(cè)邊垂直的孔，孔深與測試期間探針被放置的深度相同，從而獲取一份土壤樣本?？椎闹醒霊?yīng)當(dāng)處于測量計(jì)底部的中心。根據(jù)AS 1289.2.1.1, AS 1289.2.1.2, AS

50、1289.2.1.4, AS 1289.2.1.5, 或 AS 1289.2.1.6確定土壤的含水量。NOTES:注：1 If oversize material is present, a sample should be taken to determine the percentage by mass of the material retained on the 19.0 mm or 37.5 mm sieve, as detailed in AS 1289.5.4.1.如果存在著粒徑過大的材料，應(yīng)采集一份樣本，確定其中保留在19.0 mm 或 37.5 mm篩上材料的質(zhì)量所占的比例，

51、詳見AS 1289.5.4.1。2 Methods AS 1289.2.1.2, AS 1289.2.1.4, AS 1289.2.1.5 or, AS 1289.2.1.6 may only be used if a satisfactory correlation of the method for the soil being tested has been determined in accordance with AS 1289.2.3.1.僅當(dāng)根據(jù)AS 1289.2.3.1在用于待測試土壤的方法中確定了令人滿意的關(guān)聯(lián)性時，才能使用方法AS 1289.2.1.2, AS 1289.2

52、.1.4, AS 1289.2.1.5 ，或AS 1289.2.1.6。7 CALCULATIONS計(jì)算The following calculations shall be carried out as appropriate:根據(jù)合適的情況進(jìn)行以下計(jì)算：(a) If applicable, calculate the field density count ratio and, if required, the field moisture count ratio, by dividing the appropriate count by its corresponding field s

53、tandard count.在可用的情況下，計(jì)算場密度計(jì)數(shù)比例并且在必要的情況下，將合適的計(jì)數(shù)除以與其對應(yīng)的場標(biāo)準(zhǔn)計(jì)數(shù)得出場濕度計(jì)數(shù)比例。(b) If applicable, calculate field wet density (), in tonnes per cubic metre, at the test site, from the calibration coefficients, or read these values from the calibration charts or tables.在可用的情況下，從標(biāo)定系數(shù)中計(jì)算測試地點(diǎn)的場濕密度()，以每立方米的噸數(shù)計(jì)，或從標(biāo)

54、定圖或表格中讀取這些值。(c) If applicable, calculate the field water content (W) (mass of water per unit volume) from the following equation:在可用的情況下，通過以下方程式計(jì)算場含水量(W)（每單位體積的水的質(zhì)量）：Where 其中W field water content of the soil, in tonnes per cubic metreW為土壤的場含水量，以每立方米的噸數(shù)計(jì)d moisture slope constant determined in accorda

55、nce with AS 1289.5.8.4 d為根據(jù)AS 1289.5.8.4含水量比例確定出的水分斜率常數(shù)MCR moisture content ratioMCR為含水量比例c moisture intercept as detailed in Appendix Bc為濕度截距，詳見附錄B(d) When required, calculate the field dry density (d) from the following equation:在必要的情況下，使用以下方程式計(jì)算場干密度(d)： 其中d= field dry density of the soil, in tonn

56、es per cubic metred為土壤的場干密度，以每立方米的噸數(shù)計(jì)= field wet density of the soil, in tonnes per cubic metre為土壤的場濕密度，以每立方米的噸數(shù)計(jì)W= field water content of the soil, in tonnes per cubic metreW為土壤的場含水量，以每立方米的噸數(shù)計(jì)or, when field moisture content (w) has been determined from a field sample obtained in accordance with Cla

57、use 6 (g), calculate the field dry density (d) from the following equation:或者，當(dāng)根據(jù)第6 (g)條采集的現(xiàn)場樣本的場含水量(w)已經(jīng)確定時，可用以下方程式計(jì)算出場干密度(d)：10AS 1289.5.8.1-2007Where 其中d= field dry density of the soil, in tonnes per cubic metred為土壤的場干密度，以每立方米的噸數(shù)計(jì)= field wet density of the soil, in tonnes per cubic metre為土壤的場濕密度，

58、以每立方米的噸數(shù)計(jì)w= field moisture content of the soil, in percentw為土壤的場含水量，以百分?jǐn)?shù)計(jì)(e) When the gauge has been used to determine the field water content of the soil in tonnes per cubic metre, calculate the field moisture content (w) in percent from the following equation:當(dāng)使用了測量計(jì)確定土壤的場含水量（以每立方米的噸數(shù)計(jì)）時，用以下方程式計(jì)算場含水量(w)（以百分?jǐn)?shù)計(jì)）：where 其中w=