The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
2.0μm ± 0.4μm
直径(公制) 颗粒
2.0 ± 0.4µm
包括
Certificate of Calibration and Traceability to NIST
材料
Borosilicate Glass
粒子密度
2.5 to 2.55g/cm³
数量.
1g
折射率
1.56 at 589nm (25°C)
规格分布
s = 0.6µm, 30% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
8.3mu;m ± 0.4μm
直径(公制) 颗粒
8.3 ± 0.4µm
包括
Certificate of Calibration and Traceability to NIST
材料
Borosilicate Glass
粒子密度
2.5 to 2.55g/cm³
数量.
1g
折射率
1.56 at 589nm (25°C)
规格分布
s = 0.8µm, 9.6% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
15.9μm ± 0.6μm
直径(公制) 颗粒
15.9 ± 0.6µm
包括
Certificate of Calibration and Traceability to NIST
材料
Borosilicate Glass
粒子密度
2.5 to 2.55g/cm³
数量.
1g
折射率
1.56 at 589nm (25°C)
规格分布
s = 1.8µm, 11% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
19.3mu;m ± 1.0μm
直径(公制) 颗粒
19.3 ± 1.0µm
包括
Certificate of Calibration and Traceability to NIST
材料
Borosilicate Glass
粒子密度
2.5 to 2.55g/cm³
数量.
1g
折射率
1.56 at 589nm (25°C)
规格分布
s = 1.9µm, 9.8% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
30.1μm ± 1.1μm
直径(公制) 颗粒
30.1 ± 1.1µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 2.3µm, 7.6% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
42.3μm ± 1.1μm
直径(公制) 颗粒
42.3 ± 1.1µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 1.5µm, 3.5% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
49μm ± 1.4μm
直径(公制) 颗粒
49.0 ± 1.4µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 2.4µm, 4.9% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
60μm ± 1.3μm
直径(公制) 颗粒
60.0 ± 1.3µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 2.3µm, 3.8% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
类型
Size Standard Particles
适用于(应用)
Narrow Size Standard Deviation Applications
9070
Each
71.0 ± 1.7µm
87.96
产品规格
Each
添加剂
None
组成
Soda Lime Glass
浓度
100% solids
目录
Dry glass microspheres
描述
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
71.0μm ± 1.7μm
直径(公制) 颗粒
71.0 ± 1.7µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 2.9µm, 4.1% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
79.1μm ± 1.7μm
直径(公制) 颗粒
79.1 ± 1.7µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 2.8µm, 3.5% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
90.3μm ± 2.8μm
直径(公制) 颗粒
90.3 ± 2.8µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 3.9µm, 4.3% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
98.7mu;m ± 2.8μm
直径(公制) 颗粒
98.7 ± 2.8µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 3.0µm, 3.0% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
1106μm ± 11μm
直径(公制) 颗粒
1106 ± 11µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 28.6µm, 2.6% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
111μm ± 2.8μm
直径(公制) 颗粒
111 ± 2.8µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 4.2µm, 3.8% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
120μm ± 3.0μm
直径(公制) 颗粒
120µm ± 3.0µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 5.2µm, 4.3% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
139μm ± 2.6μm
直径(公制) 颗粒
139 ± 2.6µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 2.9µm, 2.1% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
167μm ± 3.4μm
直径(公制) 颗粒
167 ± 3.4µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 6.3µm, 3.8% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
198mu;m ± 3.4μm
直径(公制) 颗粒
198 ± 3.4µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 6.4µm, 3.2% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
2007μm ± 13μm
直径(公制) 颗粒
2007 ± 13µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 50.9µm, 2.5% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
231μm ± 4.1μm
直径(公制) 颗粒
231 ± 4.1µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 9.0µm, 3.9% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
279μm ± 3.7μm
直径(公制) 颗粒
279 ± 3.7µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 9.3µm, 3.3% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
324μm ± 8.8μm
直径(公制) 颗粒
324 ± 8.8µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 16.0µm, 4.9% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
399μm ± 8.0μm
直径(公制) 颗粒
399 ± 8.0µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 9.9µm, 2.5% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
480μm ± 9.2μm
直径(公制) 颗粒
480 ± 9.2µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 14.1µm, 2.9% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
553mu;m ± 11μm
直径(公制) 颗粒
553 ± 11µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 29.0µm, 5.2% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
645μm ± 10μm
直径(公制) 颗粒
645 ± 10µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 25.1µm, 3.9% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
749μm ± 8.5μm
直径(公制) 颗粒
749 ± 8.5µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 19.4µm, 1.9% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
940μm ± 9.8μm
直径(公制) 颗粒
940 ± 9.8µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 39.7µm, 4.2% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
5.1μm ± 0.5μm
直径(公制) 颗粒
5.1 ± 0.5µm
包括
Certificate of Calibration and Traceability to NIST
材料
Borosilicate Glass
粒子密度
2.5 to 2.55g/cm³
数量.
1g
折射率
1.56 at 589nm (25°C)
规格分布
s = 0.6µm, 12% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
1106μm ± 11μm
直径(公制) 颗粒
1106 ± 11µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 28.6µm, 2.6% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.
The 9000 Series is available as uniform particles of borosilicate or soda lime glass in a range of discrete sizes from 2 µm to 2000 µm. Calibrated and certified with NIST traceable mean diameters, they are suited for particle measurement applications. They also have a better tolerance to chemicals and solvents, and a higher mechanical and thermal stability.
直径(公制)
2007μm ± 13μm
直径(公制) 颗粒
2007 ± 13µm
包括
Certificate of Calibration and Traceability to NIST
材料
Soda Lime Glass
粒子密度
2.4 to 2.6g/cm³
数量.
1g
折射率
1.50 - 1.52 at 589nm (25°C)
规格分布
s = 50.9µm, 2.5% CV
稳定性
Product stable for a minimum of 24 months
储存要求
Store at room temperature. Keep bottle tightly sealed to avoid contamination.