Accounts for Glass Measuring Vessel
  
  　　Glass measuring vessels mentioned here are made adopting No.4 and No.5 soft material glasses introduced in page14 and page 15. The production is carried out in line with various technical standards defined in 'Trial Test Regulations for Glass Measuring Vessel' promulgated by the State Measuring Bureau of the People's Republic of China. Thus, all products have undergone strict inspection before put into market and their technical index has reached national standard.   
     
  Ⅰ.Grade classification of glass measuring vessel
　　In the light of classification rules defined in 'Trial Test Regulations for Glass Measuring Vessel', glass measuring vessel contains two kinds, namely first grade and second grade. The fist grade products are tested by means of balance testing method while second grade products are tested using comparison testing method. After classification, the measuring vessels are marked with 'First Grade' or 'Second Grade', or 'Ⅰ' or 'Ⅱ' on eye-catching places. Vessels not marked belong to second grade measuring vessels. As to now, we mainly supply second grade glass measuring vessels. If first grade is needed, please note it in order.  		  
     
 
Ⅱ.Marker on glass measuring vessels
　　Glass measuring vessels adopts ml as its measuring unit, and are marked by international symbol 'ML' or 'ml'. The standard temperature for measuring is 20℃. Vessels to measure off is marked with Chinese character '出' or 'A', those to measure in is signed with Chinese character '入' or 'E', and vessels without the mark of '出', 'A' or '入', 'E' means that they can only measure off. Meanwhile, measuring vessels with dull polished pistons or dull polished joint are all signed with same serial number in hopes of conformity. 
  
     
  Ⅲ.Measuring off time of glass measuring vessel
　　In consideration of glass surface's adhesion force, the length of time it takes for liquid to flow from the bottom of measuring vessel to the outside will effect the accuracy of volume to some extent. Hereby, as 'Trial Test Regulations for Glass Measuring Vessel' defines, the measuring off time for buret, pipet and suchlike products is fixed as per their graduated length, in order to secure correct operation in practical use. The table of measuring off times is attached in the end. (refer to table 1, 2)  		  
     
  Ⅳ.Permissible deviation from nominal capacity
　　In line with 'Trial Test Regulations for Glass Measuring Vessel' , glass measuring vessel's permissible deviation from nominal capacity as follows: (refer to table 3 to 6)		  
     
  Ⅴ.Mark of chromatic circle
　　In hopes of identifying pipets of different standards and capacities, the handles of graduated pipets and those without graduation are imprinted with different chromatic circles, according to international standard ISO1769 and Regulations on Chromatic Circle Marks on Pipet QB962, facilitating easy reorganization. Detailed regulations as follows: (refer to table 7, 8 ) 		  
     
 
　Table 1     Buret 
  
 
Nominal Capacity(ml)
1
2
5
10
25
50
100
Division Value(ml) 
0.01
0.02
0.05
0.1
0.1
0.2
Permissible Deviation(ml)
A
±0.010
±0.010
±0.025
±0.04
±0.05
±0.10
B
±0.020
±0.020
±0.050
±0.08
±0.10
±0.20
Measuring off Time of Water(s)
A
20-35
30-45
45-70
60-90
70-100
B
15-35
20-45
35-70
50-90
60-100
Latency Time(s)
30
Width of Graduation Line(mm)
≤0.4
 
     
 
　Table 2     Single-reticle Pipet
  
 
Nominal Capacity(ml)
1
2
3
5
10
15
20
25
50
100
Permissible Deviation(ml)
A
±0.007
±0.010
±0.015
±0.020
±0.025
±0.030
±0.05
±0.08
B
±0.015
±0.020
±0.030
±0.040
±0.050
±0.060
±0.10
±0.16
Measuring off Time of Water(s)
A
7-12
15-25
20-30
25-35
30-40
35-45
B
5-12
10-25
15-30
20-35
25-40
30-45
Width of Graduation Line(mm)
≤0.4
 
     
 
　Table 3      Graduated Pipet
  
 
Nominal Capacity (ml)
Division Value (ml)
Permissible Deviation(ml)
Measuring off Time of Water (s)
Width of Graduation Line (mm)
Complete Outflow Type
Incomplete Outflow 
Type
Blowoff Type
A
B
Blowoff Type
With Latency Time
No Latency Time
No Latency Time
15sA
A
B
A
B
0.1
0.001
0.005
-
±0.003
±0.004
-
-
-
2-7
2-5

Graduation≤0.3
Grade A 

 

 

Grade B≤0.4
(marking line)
0.2
0.002
0.01
-
±0.005
±0.006
0.25
0.002
0.01
-
±0.005
±0.008
0.5
0.005
0.01
0.02
-
±0.010
±0.010
1
0.01
±0.08
±0.015
±0.015
4-8
4-10
3-6
2
0.02
±0.012
±0.025
±0.025
4-12
5
0.05
±0.025
±0.050
±0.050
5-11
6-14
5-10
10
0.1
±0.05
±0.10
±0.10
7-17
25
0.2
±0.10
±0.20
-
9-15
11-21
-
50
0.2
±0.10
±0.20
-
17-25
15-25
 
     
 
　Table 4     Single-reticle Measuring Flask
  
 
Nominal Capacity(ml)
1
2
5
10
25
50
100
200
250
500
1000
2000
Permissible(ml)
A
±0.010
±0.015
±0.020
±0.020
±0.03
±0.05
±0.10
±0.15
±0.15
±0.25
±0.40
±0.60
B
±0.020
±0.030
±0.040
±0.040
±0.06
±0.10
±0.20
±0.30
±0.30
±0.50
±0.80
±1.20
Width of Graduation Line(mm)
≤0.4
 
     
 
　Table 5    Measuring Cylinder
  
 
Nominal Capacity(ml)
5
10
25
50
100
250
500
1000
2000
Division Value(ml)
0.1
0.2
0.5
1
1
2or5
5
10
20
Permissible(ml)
Inflow Measuring Type
±0.05
±0.10
±0.25
0.25
±0.5
±1.0
±2.5
±5.0
±1.0
Outflow Measuring Type
±0.10
±0.20
±0.50
±0.50
±1.0
±2.0
±5.0
±10
±20
Width of Graduation Line(mm)
≤0.3
≤0.4
≤0.5
 
     
 
　Table 6    Measuring Cup
  
 
Nominal Capacity(ml)
5
10
20
50
100
250
500
1000
2000
Permissible(ml)
1
1
2
5
10
25
25
50
100
Division Value(ml)
±0.2
±0.4
±0.5
±1.0
±1.5
±3.0
±6.0
±10
±20
Width of Graduation Line(mm)
 
     
 
　Table 7    Graduated Pipet 
  
 
Nominal Capacity(ml)
0.1
0.1
0.25
0.25
0.5
0.5
1
2
5
10
Minimal Graduation(ml)
0.001
0.005
0.0025
0.01
0.005
0.02
0.01
0.02
0.05
0.1
Color of Chromatic Circle 
Green
Red
Yellow
White
Green
Red
Yellow
Black
Red
Orange
Marked Strip Number
2
1
1
2
1
2
1
1
1
1
 
     
 
　Table 8   Pipet without Graduation
  
 
Nominal Capacity(ml)
1
2
3
5
10
15
20
25
50
100
Color of Chromatic Circle 
Blue
Orange
Black
White
Red
Green
Yellow
Blue
Red
Yellow
Marked Strip Number
1
1
1
1
1
1
1
1
1
1