《烟草专用透气度流量盘检定规程技术报告》

PAGEPAGE17《烟草专用透气度流量盘检定规程》标准修订项目实验报告《烟草专用透气度流量盘检定规程》标准修订项目的主要承担单位为中国烟草标准化研究中心（以下简称标准化中心），项目的协作承担单位是中国科学院安徽光学精密机械研究所。标准化中心和协作单位以及其它参与规程修订工作的项目组成员一起对规程的操作可行性，规程中确定的检定项目、检定指标要求与相关标准中规定的一致性进行了验证，以期达到科学、权威、可行的目的。目前行业内使用的烟草专用透气度流量盘主要是由国内外四家公司生产的，项目组根据需要选取了这四家国内外仪器公司具有代表性的18个烟草专用透气度流量盘进行了实验验证。一、实验目的新修订的《烟草专用透气度流量盘检定规程》与2002版检定规程相比，主要变化是：1、改变了烟草专用透气度流量盘在测量气路中的位置；2、增加了烟草专用透气度流量盘的结果修正方法。为了验证新修订的检定方法，确定了实验目的：1、验证烟草专用透气度流量盘测量结果的修正补偿方法；2、验证新的测量方法下，透气度流量盘测量结果的准确性，重复性以及稳定性；二、实验方法1、对烟草专用透气度流量盘的外观进行检查，确认烟草专用透气度流量盘洁净、无污损。2、烟草专用透气度流量盘按GB/T10739的要求进行温湿度平衡，平衡时间不小于6h。3、对流量盘压力流量的特性进行判定通过在流量盘两端压差分别约为0.75kPa和1.25kPa的不同压力下测量透气度流量盘的体积流量。当因子k大于0.95时，认为流量盘为线性；当因子k不大于0.95时，则认为流量盘为非线性。流量盘两端压差约为0.75kPa时的体积流量；流量盘两端压差约为1.25kPa时的体积流量；流量盘两端压差约为0.75kPa时的压差；流量盘两端压差约为1.25kPa时的压差。4、采用新的测量方法，分别在22℃，24℃两个温度点，在86kPa，93kPa，99kPa，101kPa，106kPa五个大气压力点对18个流量盘进行测量。实验数据见表1-表18。4.1线性流量盘的测量：将烟草专用透气度流量盘置于专用夹具中，打开气源开关，使用压力调节装置调节烟草专用透气度流量盘两边的气体压力差，使压差表的读数符合GB/T23227的规定。流量盘两端的气体压力稳定后，记录流量计读数。重复测量10次，计算10次流量的平均值。利用公式2将平均值修正到标准条件下，记录实验数据以及修正值。线性流量盘测量结果的修正依照以下公式：修正到标准条件下的体积流量；测试条件下的体积流量；标准条件下的大气压力；测试时实际环境大气压力；4.2非线性流量盘的测量：将烟草专用透气度流量盘置于专用夹具中，打开气源开关，使用压力调节装置调节烟草专用透气度流量盘两边的气体压力差，分别在约为800Pa，900Pa，950Pa，1000Pa，和1010Pa五个不同压力下测量流量盘流量，每个压差下重复测量10次，计算不同压差下10次流量的平均值。利用公式3将不同压差下的平均值修正到标准条件(22℃，101325Pa)下，记录实验数据以及修正值。修正到标准条件下的体积流量；标准条件下的空气动力粘度；标准条件下的空气密度；和透气度流量盘的特征参数。5、验证新的测量方法下，透气度流量盘测量结果的准确性分别用新老方法，测量透气度流量1-3，测量结果与国外原厂计量证书结果分别进行比对，结果见表19-表21。6、验证新的测量方法下，透气度流量盘测量结果的重复性用新方法，重复测量透气度流量1-3，测量结果见表22-表24。7、验证新的测量方法下，透气度流量盘测量结果的稳定性；自2011.11~2012.4，用新方法，在规定压差下分别测量透气度流量1-3，测量结果见表25-表27。8、用新方法，重复测量透气度流量1-18，计算出其极差，结果见表28。三、实验仪器根据需要选定的实验用的测试仪器如下：1、气体流量计：测量范围（0~100）L/min，准确度等级0.5级。2、气压计：测量范围（800～1500）mbar，最大允许误差±0.1mbar。3、温度计：测量范围（15~40）℃，最大允许误差±0.1℃。4、压差计：测量范围（0~10）kPa，准确度等级0.05级。四、 实验数据1、烟草专用透气度流量盘1的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差0.96线性22.38654422.2100011359.449.5670.0668.1631.7320.96线性22.39265822.2100011409.429.5398.7140.96线性229946222.2100011439.439.5329.3570.96线性22.110100022.1100011409.439.5369.5030.96线性22.610573422.6100011409.49.5019.8950.96线性248654124100011349.439.5540.0798.1051.7180.96线性23.99265024100011419.419.5238.6520.96线性23.99958423.9100011429.49.5089.2850.96线性23.610103223.6100011389.399.4969.4170.96线性23.910573123.8100011409.379.4749.8232、烟草专用透气度流量盘2的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差0.75非线性22.38654422.11000178234.8535.5922.01934.0200.1100.75非线性22.29266022.11000179034.1834.85233.9300.75非线性229945522.11000178533.5534.14133.9600.75非线性22100935221000179033.3833.97233.9400.75非线性22.610575022.5100017993333.57333.9100.75非线性248653523.91000178034.6335.3541.88733.9400.1000.75非线性23.99267023.81000178334.1234.78833.9200.75非线性23.89950123.71000179333.4734.08533.9100.75非线性23.610092223.71000178233.3633.93833.9200.75非线性23.410571923.51000179432.9233.46734.0103、烟草专用透气度流量盘3的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差1.00线性22.28654622.3100010320.5580.5640.0060.4820.1001.00线性22.49266022.5100010330.5540.5600.5111.00线性22.29947922.1100010330.5540.5600.5491.00线性22.310101722100010300.5530.5590.5571.00线性22.410574322.4100010330.5530.5580.5821.00线性23.78654023.8100010310.5570.5630.0050.4780.1011.00线性23.39266423.2100010340.5540.5600.5101.00线性23.39948323.4100010320.5530.5590.5461.00线性23.710102223.8100010330.5530.5580.5541.00线性23.610571323.5100010300.5530.5590.5804、烟草专用透气度流量盘4的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差0.51非线性22.28654322.1100010080.1570.1590.0160.1470.0010.51非线性22.39265622.2100010090.1510.1530.1460.51非线性229947822.3100010100.1450.1460.1460.51非线性22.110103722.1100010090.1450.1460.1470.51非线性22.410577322.3100010120.1410.1420.1460.51非线性23.78654623.8100010090.1570.1590.0150.1470.0010.51非线性23.69265123.7100010100.1510.1530.1460.51非线性23.69948123.6100010090.1450.1460.1460.51非线性23.710108823.7100010110.1450.1460.1460.51非线性23.810576823.7100010100.1420.1430.1465、烟草专用透气度流量盘5的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差0.51非线性22.48654622.3100010210.3790.3840.0410.3530.0030.51非线性22.29265022.3100010190.3650.3690.3520.51非线性229946522.4100010240.3460.3490.3530.51非线性22.110102022100010260.3490.3530.3520.51非线性22.210570422.4100010200.340.3430.3500.51非线性23.68654423.7100010220.380.3840.0390.3530.0020.51非线性23.59265223.6100010200.3660.3700.3520.51非线性23.49946623.6100010230.3510.3540.3520.51非线性23.610101923.6100010240.350.3540.3530.51非线性23.510572123.6100010210.3420.3450.3516、烟草专用透气度流量盘6的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差0.50非线性22.48654522.4100011148.238.3360.8467.6600.0500.50非线性22.69266322.5100011127.928.0187.6500.50非线性22.29948522.3100011127.657.7337.7000.50非线性2210101722100011067.617.6937.6800.50非线性22.410570322.3100011117.417.4907.6600.50非线性23.28654423.4100011158.258.3510.8557.6800.0400.50非线性23.59266123.3100011137.948.0417.6700.50非线性23.69946023.7100011127.667.7437.7000.50非线性23.510102123.7100011107.637.7097.6900.50非线性23.510572023.6100011097.427.4957.6607、烟草专用透气度流量盘7的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差0.50非线性22.286541221000147624.5725.0062.44623.0600.0800.50非线性22.192642221000146423.7224.10323.0200.50非线性229945822.31000144623.0123.32123.1000.50非线性22100940221000145222.7523.07723.0600.50非线性22.210570622.31000146222.2622.56023.0800.50非线性23.98654023.91000146624.6425.0572.46523.1000.0600.50非线性23.59266923.51000146623.7824.15623.0700.50非线性23.89950623.81000144623.0523.38523.0900.50非线性23.610091223.61000145322.7923.11823.0800.50非线性23.410572523.61000145722.322.59223.0408、烟草专用透气度流量盘8的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差1.00线性22.28653722.1100010050.0750.0760.0010.0650.0131.00线性22.19266022100010040.0740.0750.0681.00线性22.39945722100010050.0740.0750.0731.00线性22.110084922100010050.0740.0750.0741.00线性22.310569922.2100010050.0740.0750.0781.00线性23.58654223.6100010050.0750.0760.0010.0640.0131.00线性23.79266523.8100010060.0740.0750.0681.00线性23.69946323.6100010050.0740.0750.0731.00线性23.410090323.5100010040.0740.0750.0741.00线性23.310571223.5100010050.0740.0750.0789、烟草专用透气度流量盘9的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差1.00线性22.28653622.4100010330.5640.5700.0080.4870.1001.00线性22.29266322.1100010340.5620.5680.5201.00线性22.39945722100010320.560.5660.5551.00线性2210085622100010320.5610.5670.5641.00线性22.410574522.3100010360.5570.5630.5861.00线性23.48654123.3100010330.5630.5700.0040.4840.1041.00线性23.69266123.7100010320.5610.5670.5161.00线性23.39946023.5100010340.560.5650.5531.00线性23.810089223.8100010350.560.5660.5601.00线性23.510574823.6100010360.5610.5660.58810、烟草专用透气度流量盘10的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差0.91非线性22.58654022.5100013074.484.5480.1274.4800.0300.91非线性22.69266122.7100013044.454.5114.4600.91非线性22.39945622.1100013014.414.4714.4500.91非线性2210086122100013014.414.4674.4600.91非线性22.310570222.5100013034.374.4214.4500.91非线性23.78654823.8100013044.474.5360.1264.4700.0200.91非线性23.69266623.7100013064.444.5014.4600.91非线性23.59945623.5100013034.414.4684.4500.91非线性23.410086123.6100013034.44.4544.4600.91非线性23.310570223.6100013054.364.4094.46011、烟草专用透气度流量盘11的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差0.67非线性22.48654722.31000139620.4820.8201.41019.7000.0600.67非线性22.59266422.41000139420.0220.34019.6900.67非线性22.399456221000137019.5119.75019.6400.67非线性22100855221000137019.4319.69019.6600.67非线性22.510572722.61000138319.1719.41019.6900.67非线性23.986548241000139220.4920.8131.45119.7300.0700.67非线性23.99266623.91000138620.0120.30919.6800.67非线性23.89957423.91000139219.6219.88819.7400.67非线性23.610080923.61000138919.4619.72819.6700.67非线性23.310570923.61000138819.1319.36219.68012、烟草专用透气度流量盘12的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差1.00线性22.28654722.5100010020.0240.0240.0000.0210.0051.00线性229264522.1100010030.0240.0240.0221.00线性22.39945922100010020.0240.0240.0241.00线性22.210084222100010000.0240.0240.0241.00线性22.210570422.3100010030.0240.0240.0251.00线性23.88655123.6100010030.0240.0240.0000.0210.0051.00线性23.79265323.8100010020.0240.0240.0221.00线性23.69946723.8100010030.0240.0240.0241.00线性23.610081923.7100010020.0240.0240.0241.00线性23.510571623.5100010030.0240.0240.02513、烟草专用透气度流量盘13的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差1.00线性22.38654023100010320.5030.5080.0030.4330.0951.00线性22.29264322.4100010330.5020.5070.4631.00线性22.39944922100010300.5040.5100.5001.00线性22.310084422.1100010200.5030.5080.5061.00线性22.510569722.5100010310.5020.5070.5281.00线性23.98654424100010300.5020.5080.0040.4310.0921.00线性23.59265323.6100010310.5010.5060.4611.00线性23.49944523.4100010280.5030.5080.4961.00线性23.610080923.8100010230.5020.5070.5011.00线性23.710571423.9100010320.50.5050.52314、烟草专用透气度流量盘14的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差0.99线性22.28653622.3100010400.6780.6860.0060.5850.1250.99线性229265822.2100010430.6760.6830.6250.99线性22.39945422100010400.6720.6800.6660.99线性22.210085022.1100010360.6760.6830.6800.99线性22.410570922.5100010400.6750.6810.7100.99线性23.48654023.6100010390.6760.6840.0060.5810.1260.99线性23.69266223.6100010410.6750.6830.6210.99线性23.39945923.4100010370.6710.6780.6620.99线性23.610083423.7100010360.6750.6820.6750.99线性23.310574623.5100010410.6740.6800.70715、烟草专用透气度流量盘15的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差0.99线性22.58653522.5100013084.554.6190.0323.9380.8720.99线性22.59266522.6100013104.554.6134.2110.99线性22.39945822100013154.554.6154.5250.99线性2210084522.1100013084.534.5874.5650.99线性22.310571722.4100013164.564.6154.8100.99线性23.68654123.7100013094.544.6070.0203.9140.8680.99线性23.79265923.7100013124.544.6044.1860.99线性23.39945323.5100013144.534.5874.4820.99线性23.510081623.6100013104.534.5874.5410.99线性23.410571723.5100013164.554.6054.78216、烟草专用透气度流量盘16的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差0.97线性22.48654722.31000147224.0524.4670.05420.8714.5670.97线性22.39266222.31000148224.0624.44522.3320.97线性22.399460221000148524.0324.41423.9400.97线性22.1100845221000150124.0624.42624.3020.97线性22.610574422.61000150924.0824.42425.4370.97线性248654624100014782424.4100.05120.7094.5690.97线性23.99267623.81000147424.0224.41022.1840.97线性23.99946823.81000149923.9924.36023.7600.97线性23.710089923.71000150224.0524.40824.1660.97线性23.9105761241000150524.0424.37425.27817、烟草专用透气度流量盘17的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差1.00线性22.28654322.3100010140.2690.2720.0020.2320.0501.00线性22.29265922.2100010160.2670.2700.2471.00线性22.19950822100010200.2690.2720.2671.00线性2210101922100010200.2680.2710.2701.00线性22.410573122.5100010170.2680.2700.2821.00线性23.58654523.5100010160.2680.2710.0020.2300.0491.00线性23.49266223.4100010170.2660.2690.2451.00线性23.49950223.6100010190.2680.2710.2641.00线性23.510100823.6100010200.2670.2700.2671.00线性23.810572224100010190.2670.2690.27918、烟草专用透气度流量盘18的实验数据k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量未修正极差标准条件下流量修正后极差0.97线性22.38654122.2100011278.638.7450.0987.4621.5550.97线性22.49266122.3100011238.628.7277.9700.97线性22.29948722.2100011278.578.6678.5040.97线性22.110100822100011208.558.6488.6180.97线性22.310574522.4100011308.568.6499.0170.97线性248654324100011218.68.7110.0937.3901.5550.97线性23.99265924100011218.568.6617.8690.97线性23.99948924100011308.568.6548.4430.97线性23.610101923.6100011258.548.6358.5630.97线性23.510571323.6100011268.538.6188.94619、烟草专用透气度流量盘1的准确性实验数据方法k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量流量值与原厂证书差值原厂证书//21.99999922.61000///9.49/新方法0.96线性23.29946223.3100011469.49.519.510.0223.29946223.3100011439.49.5123.19946223.2100011439.429.52原方法//23.09958523.11000//9.489.47-0.0223.09958523.11000//9.4623.19958523.21000//9.4720、烟草专用透气度流量盘2的准确性实验数据方法k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量流量值与原厂证书差值原厂证书//21.999977231000///34.08/新方法0.76非线性22.99945522.91000178533.5534.1433.94-0.1422.99945523.01000179033.3833.9723.09945523.01000179333.4734.09原方法//23.09950123.11000//32.8232.72-1.3623.19950123.21000//32.7123.19950123.21000//32.6221、烟草专用透气度流量盘3的准确性实验数据方法k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量出口流量流量值与原厂证书差值原厂证书//21.99997122.91000///0.556/新方法1.00线性23.39948323.4100010320.5530.5590.5590.00323.39948323.4100010330.5530.55923.39948323.3100010320.5530.559原方法//23.19949723.21000//0.5620.5620.00623.29949723.31000//0.56223.29949723.31000//0.56222、烟草专用透气度流量盘1的重复性实验数据序号k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量流量值流量均值标准偏差变异系数10.96线性23.410068023.5100011469.419.519.500.010.11%20.96线性23.410068023.5100011479.419.5130.96线性23.410067923.6100011469.399.4940.96线性23.410067923.6100011439.49.5050.96线性23.510067923.6100011459.49.5060.96线性23.510067823.6100011479.419.5170.96线性23.510067823.6100011469.49.5080.96线性23.510067823.7100011449.399.4990.96线性23.510067723.7100011469.399.49100.96线性23.510067723.7100011479.399.4923、烟草专用透气度流量盘2的重复性实验数据序号k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量流量值流量均值标准偏差变异系数10.75非线性23.210092223.21000178833.433.92033.930.030.07%20.75非线性23.210092123.31000179033.3733.93030.75非线性23.210092123.31000178533.3633.96040.75非线性23.310092023.41000179033.3933.94050.75非线性23.310092023.41000178933.3833.91060.75非线性23.310091923.41000178233.3633.94070.75非线性23.310091923.51000178333.3333.92080.75非线性23.410092023.51000178333.3233.91090.75非线性23.410092023.51000178233.3533.920100.75非线性23.410091823.51000178433.3433.99024、烟草专用透气度流量盘3的重复性实验数据序号k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量流量值流量均值标准偏差变异系数11.00线性2310102223.1100010320.5550.5600.5590.0010.16%21.00线性2310102223.1100010330.5540.55931.00线性23.110102023.1100010330.5530.55941.00线性23.110101923.2100010300.5530.55851.00线性23.110101923.2100010330.5530.55861.00线性23.210101723.2100010310.5520.55871.00线性23.210101723.3100010340.5530.55881.00线性23.310101823.3100010320.5530.55991.00线性23.310102023.4100010330.5540.559101.00线性23.410101923.4100010300.5520.55825、烟草专用透气度流量盘1的稳定性实验数据年月k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量流量值流量均值标准偏差变异系数2011.110.96线性23.610103223.6100011389.399.509.510.020.16%2011.120.96线性22.110100022.1100011409.439.542012.10.96线性23.910075024100011479.419.512012.20.96线性23.710023923.8100011439.49.502012.30.96线性23.99958423.9100011429.49.512012.40.96线性229946222.2100011439.439.5326、烟草专用透气度流量盘2的稳定性实验数据年月k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量流量值流量均值标准偏差变异系数2011.110.75非线性23.610092223.71000178233.3633.9233.930.030.07%2011.120.75非线性22100935221000179033.3833.942012.10.75非线性23.610068023.61000179233.3633.892012.20.75非线性23.810023523.71000178933.433.912012.30.75非线性23.89950123.71000179333.4733.912012.40.75非线性229945522.11000178533.5533.9627、烟草专用透气度流量盘3的稳定性实验数据年月k值流量盘特性环境温度大气压力气体温度流量盘两端压差流量计与大气压压差入口流量流量值流量均值标准偏差变异系数2011.111.00线性23.710102223.8100010330.5530.5580.5590.0010.17%2011.121.00线性22.310101722100010300.5530.5592012.11.00线性23.710081823.9100010370.5520.5572012.21.00线性2310025823.1100010310.5540.5602012.31.00线性22.29947922.1100010330.5540.5602012.41.00线性23.39948323.4100010320.5530.55928、透气度流量1-18的测量值极差流量盘测量编号序号12345678910111213141516171819.5133.920.560.1470.3527.6823.080.0750.5664.4619.670.0240.5060.6824.5924.390.2698.6329.5133.930.5590.1470.3537.6923.10.0750.5664.4619.660.0240.5060.6824.5824.370.278.6439.4933.960.5590.1460.3527.6923.060.0750.5664.4519.670.0240.5070.6834.5824.390.2698.6349.533.940.5580.1470.3537.6823.080.0750.5674.4619.660.0240.5060.6824.5624.380.2698.6159.533.910.5580.1460.3537.6723.070.0750.5664.4519.630.0240.5060.6824.5824.390.2688.6369.5133.940.5580.1470.3517.6823.080.0750.5674.4619.660.0240.5050.6814.5724.40.2698.6279.533.920.5580.1470.3537.6623.090.0750.5664.4719.650.0240.5060.6824.5824.390.2688.6389.4933.910.5590.1460.3527.6723.080.0750.5664.4619.660.0240.5060.6834.624.410.2698.6599.4933.920.5590.1470.3537.6823.110.0740.5674.4619.640.0240.5070.6824.5924.390.278.63109.4933.990.5580.1460.3517.6823.080.0750.5654.4619.660.0240.5060.6824.5724.360.2698.62检定值9.5033.930.5590.1470.3527.6823.080.0750.5664.4619.660.0240.5060.6824.5824.390.2698.63极差0.0200.0800.00