C z e c h  M e t r o l o g y  I n s t i t u t e  
Circular 31,  638 00  
Brno  
 
1. ------IND- 2013 0523 CS- EN- ------ 20130926 --- --- PROJET 
 
Executive summary for the EC (is not part of this legislation)  
Graduated flasks, burettes and pipettes used to check volume are subject to national metrology 
regulation – verification. This no tified legislation concerns only initial verification of measuring 
instruments prior to their being put into operation. This type of measuring instrument is not subject to 
type approval.  
Requirements applied to these measuring instruments are based on inte rnational standards: 
EN ISO 385, EN  ISO 648, EN ISO 835 and ISO 1042 . 
(End of executive summary.)  
 
 
 
 
The Czech Metrology Institute (CMI), as the competent local body for stipulating metrological and 
technical requirements for a specified measuring instru ment and for the stipulation of test methods for 
type approval and for verification of a specified measuring instrument pursuant to § 14(1) of Act No. 
505/1990, on Metrology, as amended, and pursuant to provisions of § 172 et seq. of Act No. 500/2004, 
the Administrative Code, as amended (hereinafter the "AC"), has on 8 July 2013 commenced ex 
officio proceedings pursuant to § 46 of the AC, and based on supporting documents issues this:  
 
 
I. 
MEASURE OF A GENERAL  NATURE  
number : 0111 -OOP -C030-13 
reference no . 0313/001/13/Pos., 
 
stipulating metrological and technical requirements for specified measuring 
instruments, including test methods for verification of specified measuring 
instruments:  
 “graduated flasks, burettes and pipettes used to check volume”  
 
 
1   Basic definitions  Measure of a General Nature No.  0111 -OOP -C030-13 
2 For the purposes of this measure of a general nature, terminology and definitions contained in  VIM 
and VIML 1) and the following terminology and definitions apply:  
                                                   
1) The International Vocabulary of Metrology - Basic and General Concepts and Associated Terms (VIM) and 
the International Vocabulary of Terms in Legal Metrology (VIML) are part of the “Terminology in the Area of 
Metrology”  technical harmonisation compendium  that is publicly available at www.unmz.cz  Measure of a General Nature No.  0111 -OOP -C030-13 
3 1.1 
volumetric glassware   
a glass measuring instrument calibrated  for a certa in volume of liquid, which is indicated with a gauge 
mark or scale, and is for example used to check volume for laboratory purposes  
1.1.1  
volumetric flask   
a glass container that serves to determine the volume of a liquid by filling it to a specified  gauge  mark  
NOTE: Volumetric flasks are labelled with the symbol “In”.  
1.1.2  
pipette  
a glass tube with a narrow tip for drawing in and then discharging a precise volume of liquid  
NOTE:  Pipettes are labelled with the symbol “Ex” . 
1.1.2.1 
graduated pipette   
a pipe tte with a scale for measuring a volume of liquid  
1.1.2.2 
volumetric  (non -graduated)  pipette   
a pipette with one mark for measuring a volume of liquid  
1.1.3 
burette  
a glass tube with a stopcock at the bottom, marked with a scale, and intended for dispensin g a precise 
volume of liquid  
NOTE: Burettes are labelled with the symbol “Ex”.  
1.2 
menis cus 
the curved surface of a liquid in a tube, whose shape depends on the liquid’s surface tension  
1.3 
nominal volume   
the largest value of volume marked on volumetric g lassware  
1.4 
true volume   
the volume value of volumetric glassware obtained through measurement  
1.5 
waiting time   
the duration, specified for volumetric glass calibrated for discharged volume, starting from the end of 
discharge of  liquid just above the graduation  line until the moment the meniscus begins to be set at the 
graduation line , usually 15 s  
1.6 
discharge time   
a specified time of continuous liquid discharge from a pipette or burette, which is counted from the 
complete opening of the pipette’s suct ion opening or the opening of the burette’s stopcock to 
maximum flow until the end of continuous discharge  Measure of a General Nature No.  0111 -OOP -C030-13 
4 1.7 
discharged volume   
the volume of liquid discharged from a pipette or burette  
1.8 
partial discharge   
discharge of liquid from the zero graduation  mark in the upper part of the scale to any graduation  mark 
of a graduated pipette or burette  
1.9 
complete discharge   
discharge of liquid from any graduation  mark to the tip of a graduated pipette or burette  
1.10 
maximum permitted volume error   
the maximum permitted deviation from the nominal volume value of volumetric glass  
2   Metrological requirements  
2.1   specified service conditions  
The reference ambient temperature is 20  °C and the reference pressure is atmospheric pressure.  
2.2   Accuracy class  
Three  accuracy classes are specified:  
– classes A and AS for higher accuracy ; 
– class B for lower accuracy . 
For graduated volumetric glass of all accuracy classes, the maximum permitted volume error must not 
be greater than the volume corresponding to the smallest graduation  of the scale.  
2.3   Nominal volume  
2.3.1     The numeric value of the nominal volume of volumetric glass is chosen from the series 10  –
 20 – 25 – 50 or multiples of 10n thereof (where n is a whole negative or positive number).  
2.3.2     The numeri c value of the volume corresponding to the volume of the smallest graduation  for 
graduated volumetric glass is chosen from the series 1  – 2 – 5 or multiples of 10n thereof (where n is a 
whole positive number).  
2.3.3     The volume of measured liquid is dete rmined by the level of the surface, or meniscus, relative 
to the graduation  line of a scale or nominal volume mark.  
For transparent liquids, the lowest point of the meniscus must be at the level of the upper edge of the 
mark.  
For opaque liquids, the edge o f the meniscus must be at the level of the upper edge of the mark.  
2.4    Maximum permitted volume error  
2.4.1    Maximum permitted volume error for volumetric flasks  
The volume of volumetric flasks is defined as the volume of water at a temperature of 20  °C, 
expressed in millilitres, contained by the flask if it is filled to the upper edge of the mark while 
respecting Article 2.3.3.  Measure of a General Nature No.  0111 -OOP -C030-13 
5 The true volume of volumetric flasks may deviate from the nominal volume at most by the maximum 
permitted volume error listed  in Tables 1 and 2.  
 
Table 1 – Dimensions and maximum permitted volume errors for volumetric flasks with narrow 
necks  
Basic dimensions  Maximum permitted volume error  
Nominal volume  
 
ml Inside neck diameter  
 
mm Minimum distance of 
mark from start of 
neck  
mm Class  A 
 
ml Class  B 
 
ml 
1 7 ± 1  5 ±0.025 ±0.050 
2 7 ± 1  5 ±0.025 ±0.050 
5 7 ± 1  5 ±0.025 ±0.050 
10 7 ± 1  5 ±0.025 ±0.050 
20 9 ± 1  5 ±0.040 ±0.080 
25 9 ± 1  5 ±0.040 ±0.080 
50 11 ± 1  10 ±0.060 ±0.120 
100 13 ± 1  10 ±0.100 ±0.200 
200 15.5 ± 1 .5 10 ±0.150 ±0.300 
250 15.5 ± 1 .5 10 ±0.150 ±0.300 
500 19 ± 2  15 ±0.250 ±0.500 
1 000  23 ± 2  15 ±0.400 ±0.800 
2 000  27.5 ± 2 .5 15 ±0.600 ±1.200 
5 000  38 ± 3  15 ±1.200 ±2.400 
Table 2 – Dimensions and maximum permitted volume errors for volumetric flasks with  wide 
necks  
Basic dimensions  Maximum permitted volume error  
Nominal volume  
 
ml Inside neck diameter  
 
mm Minimum distance of 
mark from start of neck  
mm Class A  
 
ml Class B  
 
ml 
1 9 ± 1  5 ±0.040 ±0.080 
10 9 ± 1 5 ±0.040 ±0.080 
20 11 ± 1 5 ±0.060 ±0.120 
25 11 ± 1 5 ±0.060 ±0.120 
50 13 ± 1 10 ±0.100 ±0.200 
1 000  27.5 ± 2.5 15 ±0.600 ±1.200 
 
2.4.2     Maximum permitted volume error for graduated pipettes  
The volume of graduated pipettes is defined as the volume of water at a temperature of 20  °C, 
expressed  in millilitres, discharged from a graduated pipette from the zero graduation  line to any 
graduation  line of individual volumes toward s the discharge tip.  Measure of a General Nature No.  0111 -OOP -C030-13 
6 Discharge volume errors must not exceed the maximum permitted error values listed in Table 3. These 
limits represent the maximum permitted volume errors at any point of the scale and also the maximum 
permitted difference between volume errors at any two points.  
Table 3 – Volumes, graduation s and maximum permitted volume errors for  graduated pipettes  
Nomin al volume  Smallest scale 
graduation  Maximum permitted volume errors  
Accuracy classes  A and AS Accuracy class  B 
ml Ml Ml ml 
0.1 0.01 ±0.006 ±0.01 
0.2 0.01 ±0.006 ±0.01 
0.5 0.01 ±0.006 ±0.01 
1 0.01 ±0.007 ±0.01 
1 0.1 ±0.007 ±0.01 
2 0.02 ±0.010 ±0.02 
2 0.10 ±0.010 ±0.02 
5 0.05 ±0.030 ±0.05 
5 0.10 ±0.030 ±0.05 
10 0.1 ±0.05 ±0.1 
20 0.1 ±0.1 ±0.2 
25 0.1 ±0.1 ±0.2 
25 0.2 ±0.1 ±0.2 
 
2.4.3    Maximum permitted volume error for volumetric pipettes   
The volume of volumetric pipettes is defined as the volume of water at a temperature of 20  °C, 
expressed in millilitres, discharged from a volumetric pipette from the nominal volume zero 
graduation  line toward s the discharge tip.  
Discharge volume errors must not exceed the maximum permitted error values lis ted in Table  4.  
Table 4 – Nominal volumes and maximum permitted volume errors  
Nominal volume  Maximum permitted volume errors  
Accuracy classes A and AS  Accuracy class B  
ml ml Ml 
0.5 ±0.005 ±0.010 
1 ±0.008 ±0.015 
2 ±0.010 ±0.02 
5 ±0.015 ±0.03 
10 ±0.02 ±0.04 
20 ±0.03 ±0.06 
25 ±0.03 ±0.06 
50 ±0.05 ±0.10 Measure of a General Nature No.  0111 -OOP -C030-13 
7 100 ±0.08 ±0.15 
 
2.4.4    Maximum permitted error for burettes  
The volume of burettes is defined as the volume of water at a temperature of 20  °C, expressed in 
millilitres, discharged from a burette  from any graduation  line for individual volumes to the zero value 
in front of the discharge stopcock.  
Discharge volume errors must not exceed the maximum permitted error values listed in Table 5.  
Table 5 – Nominal volumes and maximum permitted volume erro rs 
Nominal volume  Smallest scale 
graduation  Maximum permitted volume errors  
Accuracy classes A and AS  Accuracy class B  
ml ml ml Ml 
1 0,01 ±0,006  ±0,01 
2 0,01 ±0,01 ±0,02 
5 0,01 ±0,01 ±0,02 
5 0,02 ±0,01 ±0,02 
10 0,02 ±0,02 ±0,05 
10 0,05 ±0,03 ±0,05 
25 0,05 ±0,03 ±0,05 
25 0,10 ±0,05 ±0,10 
50 0,10 ±0,05 ±0,10 
100 0,20 ±0,10 ±0,20 
3   Technical requirements  
3.1   Measuring instrument design  
3.1.1     Measuring instrument appearance and shape  
3.1.1.1    The axis of the part of the volumetric glass w ith a scale must be vertical. Graduated flasks 
must stand on a horizontal base surface without rocking.  
3.1.1.2    The discharge tip of pipettes and burettes must be solid, smooth and slightly conical, without 
a sudden narrowing of the opening.  
3.1.1.3     The shape of pipettes and burettes must enable liquid to flow out evenly.  
3.1.2     Scales and marks  
3.1.2.1     Graduation lines , marks, numbering and labelling must be easy to read, permanent and 
resistant to conditions of use.  
3.1.2.2    The graduation line s of the scale must have the same thickness, and their maximum thickness 
must not be greater than half the linear equivalent of the maximum permitted volume error.  
On graduated volumetric glassware, the maximum thickness of a graduation line must not excee d one 
quarter of the minimum distance between the centres of adjacent graduation lines.  Measure of a General Nature No.  0111 -OOP -C030-13 
8 On volumetric glassware that is not graduated, the gauge mark is applied around its entire 
circumference; a gap not greater than 10% of the circumference is permitted.  
3.1.2.3    All graduation lines on the scale must be perpendicular to the longitudinal axis of the part of 
the volumetric glassware with the scale. For flat -bottomed volumetric flasks, the gauge mark must be 
parallel to the base.  
3.1.2.4    Distances between  the graduation lines on a scale must not exhibit any visible irregularities.  
3.1.2.5    Graduation lines on a scale must be applied to the cylindrical part of volumetric glassware at 
least 10 mm away from where its cross -section changes. In some cases, esp ecially for Class B 
volumetric glassware, graduation lines can also be located on parts that do not have a circular cross -
section or on a conical section of the volumetric glass.  
On volumetric glassware with one gauge mark, the number indicating the nomina l volume can be 
located along with other information, and need not be located beside the gauge mark.  
On volumetric glassware with one main graduation line and a small number of auxiliary graduation 
lines, the number indicating the nominal volume can be loc ated away from the graduated scale along 
with other information, if the auxiliary graduation lines are properly labelled.  
On graduated products with a circular cross -section, the length of the graduation lines must differ 
enough to be discernible.  
3.1.3     Materials used  
Volumetric glassware is usually manufactured from hydrolytic -grade glass with a longitudinal thermal 
expansion coefficient of  = 3,3 × 10-6 K-1 (β = 3 ×  = 9,9 ×  10-6 K-1). The glassware is characterised 
by a high degree of resistance to the effects of water, water vapour, acids and saline solutions, and 
relatively good resistance to alkalis. If a different material is used, the manufacturer must declare its 
longitudinal thermal expansion coefficient.  
The glass ware must be without visible defects and with as little internal tension as possible.  
3.2    Measuring instrument types and overall dimensions  
Volumetric glassware must be manufactured with an evenly graduated scale or with one gauge mark 
indicating the volume for filling or emptying.  Numbering of the graduated scale and gauge mark gives 
the volume in ml or cm3. Volumetric glassware is classified into several types, and must meet the 
requirements outlined in the following tables.  
3.2.1  Volumetric flasks  
The basic body shape of graduate d flasks must correspond to Table 6, and basic dimensions to Table 1 
or 2. 
Table 6 – Flask body shape  
Nominal volume  
Ml Flask body shape  
1 and 2 Conical  
5 to 50 Conical or round  body  
100 to 5 000  Round  body  
 
3.2.2    Graduated pipettes  
The basic shape a nd dimensions of graduated pipettes must correspond to Table 7.  Measure of a General Nature No.  0111 -OOP -C030-13 
9 Table 7 – Dimensions  
  Nominal volume  
ml 
0.1 0.2 0,5 1 2 5 10 20 25 25 
Smallest graduation  ml 0.01 0.01 0.1 0.01 0.02 0.05 0.1 0.1 0.1 0.2 
   0.10 0.10 0.10     
Basic dimensions in  mm 
Distance from the zero division line to the last 
division line for type 1 pipettes  min. 
max.  80 
170 120 
200 130 
220 160 
220 160 
220 140 
220 140 
220 140 
220 220 
290 180 
220 
Distance from the highest to the lowest 
numbered division line for type 2, 3 and 4  
pipettes  min. 
max.  70 
160 110 
190 110 
220 140 
220 140 
220 140 
220 140 
220 140 
220 200 
290 160 
220 
Distance from the highest division line to the 
top of the pipette  min. 100 
Minimal outer diameter of a suction tube   5.25 to 9 5.5 to 9 
Length of the stra ight part of the tube under the 
lowest division line  min. 5 
 
Classification of graduated pipettes by type  
Type 1: Partial discharge  
Graduated pipettes are calibrated for discharge of liquid from the zero division line in the upper part of 
the graduated pi pette to any graduation line, with the nominal volume given by the lowest graduation 
line. 
Type 2: Complete discharge  
Graduated pipettes are calibrated for discharge of liquid from any graduation line to the tip, with 
nominal volume given by the highest gr aduation line.  
Type 3: Complete discharge  
Graduated pipettes are calibrated for discharge of liquid from the zero division line in the upper part of 
the graduated pipette to any graduation line, with the nominal volume given by the discharge of the 
liquid down to the tip.  
Type 4: Blow -out 
Graduated complete discharge pipettes (see type 3), where the remaining drop of liquid is expelled by 
blowing it out.  
3.2.2.1     Class A, AS and B graduated partial discharge pipettes (type 1)  
Volumes and discharge times f or graduated pipettes must correspond to Table 8.  Measure of a General Nature No.  0111 -OOP -C030-13 
10 Table 8 –Discharge times for type 1 graduated pipettes  
Nominal 
volume  
 
ml Smallest 
scale 
division  
ml Discharge time  
Class  A Class  AS Class  B 
s (min.)  s (max.)  s (min.)  s (max.)  s (min.)  s (max.)  
0.1 0.01 2 3 – – 2 3 
0.2 0.01 2 4 – – 2 4 
0.5 0.01 – – 4 10 2 11 
1 0.01 7 10 4 10 2 11 
1 0.1 2 10 4 10 2 11 
2 0.02 8 12 4 10 2 12 
2 0.10 2 12 4 10 2 12 
5 0.05 10 14 7 13 5 14 
5 0.10 4 14 7 13 5 14 
10 0.1 13 17 7 13 5 17 
20 0.1 – – 11 17 9 21 
25 0.1 15 21 11 17 9 21 
25 0.2 5 15 – – 5 15 
 
3.2.2.2     Class A, AS and B graduated full discharge pipettes (type 2)  
Volumes and discharge times for graduated pipettes must correspond to Table  9. 
Table 9 – Discharge times for type 2 graduated pipettes  
Nominal 
volume  
 
ml Smallest 
scale 
division  
ml Discharge time  
Class A  Class A  Class A  
s (min.)  s (max.)  s (min.)  s (max.)  s (min.)  s (max.)  
0.1 0.01 1 3 – – 1 3 
0.2 0.01 1 4 – – 1 4 
0.5 0.01 – – 4 10 2 11 
1 0.01 5 7 4 10 2 11 
1 0.10 2 7 4 10 2 11 
2 0.02 6 9 4 10 2 12 
2 0.10 2 9 4 10 2 12 
5 0.05 8 11 7 13 5 14 
5 0.10 4 11 7 13 5 14 
10 0.1 10 13 7 13 5 17 
20 0.1 – – 11 17 9 21 
25 0.1 11 16 11 17 9 21 
25 0.2 11 16 – – 9 21 
 Measure of a General Nature No.  0111 -OOP -C030-13 
11 3.2.2.3    Class A, AS and B graduated full discharge pipettes (type  3) 
The w aiting time for these pipettes is specified as 5 s.  
Volumes and discharge times for graduated pipettes must correspond to Table  10. 
Table 10 – Discharge times for type 3 graduated pipettes  
Nominal 
volume  
 
ml Smallest 
scale 
division  
ml Discharge time  
Class A Class A  Class A  
s (min.)  s (max.)  s (min.)  s (max.)  s (min.)  s (max.)  
0.1 0.01 1 3 – – 1 3 
0.2 0.01 1 4 – – 1 4 
0.5 0.01 - - 4 10 2 11 
1 0.01 5 7 4 10 2 11 
1 0.10 5 7 4 10 2 11 
2 0.02 6 9 4 10 2 12 
2 0.10 6 9 4 10 2 12 
5 0.05 8 11 7 13 5 14 
5 0.10 8 11 7 13 5 14 
10 0.1 10 13 7 13 5 17 
20 0.1 – – 11 17 9 21 
25 0.1 11 16 11 17 9 21 
25 0.2 11 16 – – 9 21 
 
3.2.2.4    Blow -out graduated pipettes  (type 4) 
Volumes and discharge times for graduated pipettes must correspond to Table  11. 
Table 11 – Discharge times for  type 4 blow -out pipettes  
Nominal 
volume  
 
ml Smallest scale 
division  
Ml Discharge time  
Class  B 
s (min.)  s (max. ) 
0.1 0.01 1 3 
0.2 0.01 1 4 
1 0.01 2 7 
1 0.10 2 7 
2 0.02 2 7 
2 0.10 2 7 
5 0.05 4 10 
5 0.10 4 10 
10 0.1 4 10 
25 0.2 5 15 
 Measure of a General Nature No.  0111 -OOP -C030-13 
12 3.2.3    Volumetric pipettes of class  A, AS a nd B  
Volumes and discharge times for volumetric pipettes must correspond to Table  12. 
Table 12 –Discharge time in seconds  
Nominal volume  
ml  0,5 1 2 5 10 20 25 50 100 
Class  A min. 10 10 10 15 15 25 25 30 40 
max.  20 20 25 30 40 50 50 60 60 
Class  AS min.  6 7 7 9 11 12 15 20 25 
max.  10 11 11 13 15 16 20 25 30 
Class  B min.  4 5 5 7 8 9 10 13 25 
max.  20 20 25 30 40 50 50 60 60 
Difference between the 
marked and measured 
discharge time  max.  2 2 2 3 3 4 4 5 5 
 
3.2.4    Burettes   
3.2.4.1     Burettes without a waiting time  
Volumes, dimensions and discharge times of burettes must correspond to Tables 13 and 14.  
Table 13 –Dimensional requirements  
Nominal volume  Smallest division  Scale length  Total le ngth 
ml ml mm (min.)  mm (max.)  mm (max.)  
1 0,01 150 200 575 
2 0,01 200 300 650 
5 0,01 480 600 820 
5 0,02 250 600 800 
10 0,02 480 600 820 
10 0,05 250 450 620 
25 0,05 480 600 820 
25 0,10 250 450 620 
50 0,10 500 600 820 
100 0,20 550 650 870 
 Measure of a General Nature No.  0111 -OOP -C030-13 
13 Table 14 – Discharge time  
Nominal volume  
 
ml Smallest scale 
division  
 
ml Discharge time  
Accuracy class  A Accuracy class  B 
s (min.)  s (max.)  s (min.)  s (max.)  
1 0.01 20 50 20 50 
2 0.01 15 45 10 45 
5 0.01 20 75 20 65 
5 0.02 20 75 20 65 
10 0.02 75 95 40 95 
10 0.05 75 95 45 75 
25 0.05 70 100 30 70 
25 0.10 35 75 30 70 
50 0.10 50 100 40 100 
100 0.20 60 100 30 100 
 
3.2.4.2    Burettes with waiting time  
The waiting time for these burettes is specified as 30 s.  
Volumes, dimensions and discharge times of b urettes must correspond to Tables  13 and 15. 
 
Table 15 – Discharge time  
Nominal volume  
ml Smallest scale division  
ml Discharge time  
s (min.)  s (max.)  
2 0.01 8 20 
5 0.01 15 25 
5 0.02 15 25 
10 0.02 35 45 
10 0.05 35 45 
25 0.05 35 45 
25 0.10 35 45 
50 0.10 35 45 
4   Measuring instrument labelling  
Volumetric glass must be labelled with the following information:  
a) the manufacturer;  
b) the nominal volume with the unit of measure;  
c) accuracy class A, AS or B;  Measure of a General Nature No.  0111 -OOP -C030-13 
14 d) the “In” symbol indicating that the product has bee n calibrated to contain or the symbol “Ex” 
indicating that the product has been calibrated to deliver;  
e) a reference temperature of  20 °C; 
f) the maximum permitted error;  
g) products for which a waiting time is prescribed must be labelled for example as “Ex + 5 s” ; 
h) other information according to user requirements (must not be at odds with points a) to h)).  
5   Measuring instrument type approval  
These measuring instruments are not subject to type approval pursuant to the Metrology Act.  
6   Initial verification  
6.1    Overview of tests performed  
The process for initial verification of volumetric glassware inc ludes the following steps:  
a) a visual inspection;  
b) a check of the volumetric glassware’s dimensions;  
c) an accuracy test; for pipettes and burettes with a discharge tim e test.  
6.2    Visual inspection  
During a visual inspection, volumetric glassware submitted for initial verification is checked whether 
it meets the appropriate technical requirements pursuant to Chapter 3, and attention must be paid to 
whether it is corre ctly labelled, rendition of volume markings, and how volume is marked.  
Volumetric glass must not be physically damaged or deformed and must be entirely clean.  
Volumetric glass that fails a visual inspection is disqualified from further testing.  
6.3   Funct ional tests  
6.3.1     Test equipment accuracy requirements  
For volume and dimension tests, regular laboratory equipment is used along with the following 
measuring instruments:  
a) reference scales of accuracy class II and III with weighing capacity correspondin g to the 
measured volume;  
b) reference weights of accuracy class II and III corresponding to the mass of the measured 
volume;  
c) a glass thermometer with a measurement range of  (0 – 50) °C, graduated in steps of 0.1  °C; 
d) a stopwatch with readout accuracy of 1 s;  
e) a calliper gauge for measuring length with an accuracy of 0.02 mm, a flexible steel ruler up to 
300 mm;  
f) a magnifying glass with at least 6x magnification.  
The reference scales, reference weights, barometer, thermometer and stopwatch must have a valid 
metrological traceability with the uncertainty given.  
The total uncertainty in establishing measurement instrument error must be at least three times smaller 
than the value of the maximum permitted error specified for the volumetric glassware being tested.  Measure of a General Nature No.  0111 -OOP -C030-13 
15 6.3.2   Dimension check  
Technical parameters and dimensions of volumetric glass are checked according to tables with the 
given dimensions.  
Volumetric glass that fails a check of basic dimensions is disqualified from further testing.  
6.3.3    Accuracy test, fo r pipettes and burettes with a discharge time test  
The accuracy of the volume of volumetric glassware is performed using the mass (gravimetric) 
method for contained volume (In) or delivered volume (Ex).  
6.3.3.1    Determining the volume of volumetric conta iner glassware marked with the “In” 
symbol  
First, the mass of an empty, degreased, clean and dried volumetric flask m1 is determined. After it has 
been filled with distilled water (on a level surface and without bubbles) up to the gauge mark with the 
menis cus correctly set to the upper edge of the gauge mark, the mass of the full volumetric flask m2 is 
determined. The mass of the volume of distilled water mi is determined by calculating the difference in 
mass mi = m2 – m1. 
Weighing must be performed quickly  and immediately after weighing the temperature of the distilled 
water, air temperature and barometric pressure are measured.  
6.3.3.2    Determining the volume of volumetric delivery glassware marked with the “Ex” symbol  
First, the mass of an empty, degrea sed, clean and dried weighing bottle m1 is determined.  
Pipettes and burettes are filled with distilled water up to the gauge mark with the meniscus correctly 
set, the required volume is discharged into the weighing bottle and the discharge time is measured , 
which is given in tables for individual types of volumetric glass.  
If pipettes and burettes meet the discharge time requirement, they are wetted and filled with distilled 
water (must not contain bubbles) up to the gauge mark of the required volume with t he meniscus 
correctly set, the required volume is discharged into the weighing bottle, and the mass of the filled 
weighing bottle m2 is measured.  
The mass of the volume of distilled water mi is determined by calculating the difference in mass : 
mi = m2 – m1. 
Weighing must be performed quickly and immediately after weighing the temperature of the distilled 
water in the supply container  and air temperature and barometric pressure are measured.  
6.3.3.3   Processing accuracy test results  
The measured values are used in the calculations below.  
Volume Vi, which corresponds to the ascertained mass mi, is calculated using a correction factor Z, 
which includes the corresponding density of distilled water at the measured temperature during 
weighing, correction for air pressure and temperature, if the temperature during the test is not 20  °C 
and the manufacturer provides a thermal expansion coefficient β (β = 3 × ) for the material out of 
which the volumetric glassware is made. The correction factor Z is calculated using the formula:  
  20 10008110001 






 t Z 
vzduchu
vzduchu vody
 
where  
 is the air density determined from mean values of air pressure and ai r temperature 
during weighing,  
 is the density of distilled water corresponding to the mean value of temperature 
ascertained during weighing,  Measure of a General Nature No.  0111 -OOP -C030-13 
16 β is the thermal expansion coefficient of the material from which the volumetric 
container i s made,  
t the temperature of the distilled water during weighing.  
The volume  Vi is calculated using the formula : 
ZmVi i
 
The ascertained volume of distilled water must not differ from the nominal value by more than the 
maximum permitted erro r pursuant to Article 2.4 for the corresponding type of volumetric glassware.  
6.3.4     Placing an official mark on the measuring instrument  
Volumetric glassware that during testing performed pursuant to this measure of a general nature has met 
its requirem ents is given an official mark by engraving, etching, sandblasting or printing.  
7    Subsequent verification  
Subsequent verification of volumetric flasks, burettes and pipettes used to check volume is not 
performed.  
8   Notified standards  
To specify metrol ogical and technical requirements for measuring devices and to specify verification 
and type approval test methods stemming from this measure of a general nature, the CMI notifies 
Czech technical standards, other technical standards or technical documents of international or foreign 
organisations or other technical documents containing detailed technical requirements (hereinafter 
"notified standards"). The CMI will publish a list of these notified standards, with their assignation to 
relevant measures, alon g with the measure of a general nature, in a manner available to the public (on 
the website www.cmi.cz).  
Compliance with notified standards or parts thereof is considered, to the extent and under the 
conditions stipulated by a measure of a general nature, to be compliance with those requirements 
stipulated by this measure to which these standards or parts thereof apply.  
 
 
II. 
JUSTIFICATION  
The CMI issues, towards the implementation of § 24c of the Metrology Act, this measure of a general 
nature, stipulatin g metrological and technical requirements for specified measuring instruments and 
test methods for verification of these specified measuring instruments.  
In Decree No 345/2002, specifying measuring instruments for mandatory verification and measuring 
instruments subject to type approval, as amended, the annex "List of Specified Measuring Device 
Types" classifies volumetric flasks, burettes and pipettes used to check volume under item 1.3. 3 as 
measuring instruments subject to verification.  
The CMI thus issue s, towards the implementation of § 24c of the Metrology Act for volumetric flasks, 
burettes and pipettes used to check volume , this measure of a general nature, stipulating metrological 
and technical requirements for volumetric flasks, burettes and pipette s used to check volume  for 
verification of these specified measuring instruments.  
This regulation (Measure of a General Nature) has been notified in accordance with Directive 
98/34/EC of the European Parliament and of the Council of 22 June 1998 laying dow n a procedure for Measure of a General Nature No.  0111 -OOP -C030-13 
17 the provision of information in the field of technical standards and regulations, as amended by 
Directive 98/48/EC.  
 
 
III. 
INSTRUCTIONS  
A measure of a general nature cannot be appealed: § 173(2) of the Administrative Code.  
Pursuant to § 172(5) of the Administrative Code, a decision on objections cannot be appealed.  
Conformance of a measure of a general nature with legislation can be judged in review proceedings 
pursuant to § 94 to 96 of the Administrative Code. A participant may ask the ad ministrative body that 
issued this measure of a general nature to carry out  a review. If the administrative body does not see any 
reason to commence review proceedings, it shall inform the submitter of this fact within thirty days, 
giving reasons. Pursuant  to § 174(2) of the Administrative Code, a ruling on the commencement of 
review proceedings can be issued within three years of the effective date of the measure of a general 
nature.  
 
IV. 
EFFECTIVE DATE  
This measure of a general nature shall take effect on  the fifteenth day following the day of its 
publication  (§ 24d of the Metrology Act).  
 
 
 
 ...………………… …………..............  
 RNDr. Pavel  Klenovský  
 Director General