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• SCHOTT INSTRUMENTS GmbH, Mainz, Germany for HOT PLATES
• S. Brannan & Sons Ltd., Cumbria, United Kingdom for BRANNAN Brand Thermometers.
  
• Heinz Herenz GmbH, Hamburg, Germany for STERISTOPPERS

The Company also has its own in-house brands meeting the quality standard

• RIVIERA
• RIVOTEK

RIVIERA encompasses a whole range of laboratory glassware, moulded and Volumetric
RIVOTEK covers a large range of laboratory Equipments.

DURAN laboratory bottles are chemically resistant and stable. When fitted with a plastic pouring ring dripping can be totally eliminated. As there is only one size screw thread for all bottles from 100 ml onwards, the screw caps and pouirng rings are fully interchangeable. The bottles, pouring rings and caps are autoclavable and sterilizable.

PROPERTIES:

Light protection

• Amber bottles upto 500 nm
• Plastic coated bottles upto 380 nm useable as safe storage for chemicals

Safe closure ensures storage of products as

• Dairy products
• Serums are kept sterile

High resistance to thermal shock

HANDLING :

Freezing substances

Recommendation: When freezing, always place the bottles at an angle (approx. 45°) and do not fill to more than 3/4 capacity (to increase surface area). Temperature limit -40°C as the plastic caps and pouring rings do not withstand lower temperatures.

Thawing forzen substances

The frozen material can be thawed by immersing the bottle in a liquid bath taking care that the temperature difference does not exceed 100°C. This will ensure that the frozen material is heated uniformly from all sides without damaging the bottle. It can, however, also be thawed slowly so
that the surface melts first, allowing the material to expand.

Sterilization

Bottles can be steam sterilized after washing. Following are the recommendation and guidelines:

Steam sterilization refers to "the destruction or irreversible inactivation of all micrgorganisms capable of reproduction" (DIN 58900, pt1, 1986) by means of "saturated steam at a minimum of 120°C and 2 bar" (DIN 58946, pt1, 1987). The minimum effective application time (destruction time + safety factor) is indicated in DIN 58946, pt2 as a duration of 20 minutes at a sterilization temperature of 121 °C.

The following should be noted with respect to preparation for sterilization

• Soiled bottles must be cleaned first, otherwise microorganisms cannot be effectively destroyed and chemicals adhereing to the surface can damage it as a result of high temperature involved.
• To aviod a build up of pressure the screw cap should be left loose on the bottle neck (one turn maximum). It should not be closed tight as the pressure then cannot be balanced and the consequent difference in pressure can result in the bottle bursting.
• Ensure that saturated stem is used and that it has unhindered access to all contaminated places. This is the only way to achieve effective steam sterilization.

LABORATORY BOTTLES WITH PLASTIC COATING, DURAN

The resistant and transparent copolymer based plastic coating bonds firmly with the blast surface and performs the following functions:

• Protects the glass surface against mechanical damage (Scratch protection)
• Holds the fragments together in the event of the glass breaking (Splinter protection)
• Minimises liquid loss in the event of the glass breaking (Protection against contents escaping and spraying)
• Absorbs UV rays upto a light wavelength of 380 nm (Light protection)

Do not expose plastic coated bottles to open flames or direct heat, e.g. on a laboratory hot plate. The maximum operating temperature is 135°C. Bottle should not be exposed to this temperature for more than 30 minutes.

Plastic coated bottles are suitable for freezing (-30°C)and it can also be used in microwaves. However, the plastic coating does not increase the permissible pressure at which they can be used.

Cleanliness of glass surface

             The volume contained in or delivered by a glass vessel depends on the cleanliness of the internal glass surface of the vessel. Lack of cleanliness can give rise to error through a badly shaped meniscus involving two defects.

• Incomplete wetting of the glass surface i.e., the liquid surface meets the glass at an appreciable angle instead of forming a curve such that it meets the glass tangentially.
  
• A generally increased radius of curvature due to contamination of the liquid surface reducing the surface tension.
  

        In vessels used for delivery, lack of cleanliness can cause additional errors due to the film of liquid on the walls being irregularly distributed or incomplete. Where vessels are fitted with ground stoppers special attention shall be paid to cleaning the ground zone.
To ascertain whether a delivery vessel is satisfactorily clean, it shall be observed during filing. A delivery vessel should preferably be filled from below the liquid surface i.e. through the stopcock in the case of a burette or through the jet of a pipette. The rising liquid meniscus shall not change shape i.e. it shall not crinkle at its edges. After overfilling and withdrawing a little liquid the surface of the glass above shall remain uniformly wetted and the meniscus shall not crinkle at its edges.


Setting of the meniscus

          Most items of volumetric glassware employ the principle of setting or reading a meniscus (the interface between air and the liquid, the volume of which is being measured) against a reference line or scale.
The meniscus shall be set so that the plane of the upper edge of the graduation line is horizontally tangential to the lowest point of the meniscus, the line of sight being in the same plane. In the case of a mercury meniscus, the highest point of the meniscus shall be set to the lower edge of the graduation line. The lighting should be arranged so that the meniscus appears dark and distinct in outline. For this purpose, it should be viewed against a white background and shaded from undesirable illumination. Parallax is avoided when the graduation lines are of sufficient length to be seen at the front and back of the vessel simultaneously.


Delivery Time
For articles used for delivery of a liquid, the volume delivered is always less than the volume contained, due to the film of liquid left on the walls of the vessel. The volume of this film depends on the time taken to deliver the liquid, and the volume decreases with decreasing delivery time.

The EM TECHCOLOR branded conformity certified volumetric glassware with dated batch identification manufactured by Hirschmann Laborgerate is ideal for the documentation of volumetric measurement and for the total traceability as demanded by ISO 9000.

All the volumetric glassware manufactured by Hirschmann Laborgerate are conforming to three international standards. They are DIN, ISO and PTB.

DIN is a German standard and is widely recognized in all the advanced countries. Therefore, it is accepted as an international standard.

PTB (Physikalisch-Technische Bundesanstalt) is a state science institute in Germany, which is the highest technical governmental authority in the service of the State Minister of Economics having in their employment about 1900 persons, whereof 500 are scientists. Major assignments of this institute are:

• Definition of Precision for Physical Constants
  
• Design Examination and Approval of Measures
  
• Design Examination in the field of Safety Technics, Radiation Protection, Medicine etc.
  
• Elaboration of Technical Prescriptions and Laws
  
• Calibration, Order Examination and Scientific Technic Consultancy
  
• Education and Development Aid in Measure Technology
  

Their publications are:

• 2 monthly issues on science and official publication of PTB
  
• Yearly report of PTB
  
• PTB reports – specific individual publications
  
• PTB examination rules – Rules for examination of measures and accessories with description of examination methods
  
• Eichordnung – Laws for the approval, calibration and examination of measures
  
• Eichanweisung – direction lines for examination, calibration and surveillance of measures
  
• PTB requirements – technical requirements of measures which must be officially tested
  
• Technical rules – information and recommendation for official acceptance of examination places for measures
  

The standards, which PTB describes, become LAW in Germany. And those who confirm to produce according to these standards are under governmental surveillance in production control.

International Standard (ISO) 4787 – Methods for use and testing of capacity

ISO 4787 gives the detailed procedure for use and testing of capacity of volumetric glassware.

According to it the following apparatus and materials are required for conducting the examination.

Balance – a laboratory balance with sufficient capacity to weigh the loaded vessel is required. A single pan, a self- indicating instrument or an equal arm balance of adequate discrimination and capacity may be used. Its discrimination should not exceed 1/10 of the limits of error of the instrument to be tested
         

Thermometer – to measure the temperature of the water and its limits of error shall be 0.1°C

Barometer – It should be capable of providing atmospheric pressure measurements consistent with appropriate tolerances. Its limits of error shall be 1 mbar

Water – Distilled or deionized water, suitable for general laboratory purpose shall be used
 

Factors affecting the accuracy of volumetric glassware
 
Temperature – Vessel and Liquid

            The capacity of a glass vessel varies with change of temperature; the particular temperature at which a vessel is intended to contain or deliver its nominal capacity is the reference temperature of the vessel. A vessel made of soda lime glass adjusted at 20°C but used at 27°C would, at the temperature of use, show an extra error of only 0.02%, which is smaller than the limits of error for most articles of volumetric glassware. It follows, therefore, that the reference temperature is of minor importance in practical use of the glassware, but in order to provide a sound basis for adjustment it is important to specify a reference temperature and the vessel should be equilibrated at that temperature before testing. 
            
            Temperature of the water used for the testing of volumetric glassware shall be accurately measured to within ± 0.1°C. Corrections for differences in temperature shall be applied.
 

            It follows, therefore, that such a vessel can deliver a particular volume for one value only of the delivery time. The shorter the specified delivery time, the greater is the variation in the volume delivered due to small variations in delivery time, which inevitably occur. Provided that the delivery time is never less than a certain value, the volume of the residual film is sufficiently small and uniform to ensure that departures from the nominal delivery time which occur in practice have a negligible effect on the volume delivered and that the drainage occuring after delivery is negligibly small.
 
 
Validity of Calibration
 
             The standards for laboratory measuring instruments do not specify a validation of calibration. This is obviously so as it depends on the usage of the instruments by the users. If a volumetric cylinder stands unused or used for reports (in extreme cases once per year only) then the volume is still correct after 5-10 years. But, if a flask is filled, cleaned, autoclaved continuously with glass attacking liquids, the volume might change after some time.
 

 DURAN bottles can generally withstand a temperature of -70°C, but not with Blue PP or Red PBT caps. The reason is that PP or PBT can withstand the temperature on the lower side only upto -40°C. Therefore, the liquid can be frozen in the bottles without any PP/PBT caps. However, a user has to follow a number of safety procedures before using it below 40°C. They are:

• The bottles should not be filled up to the maximum. It should have three quarters of the bottles filled.
• The bottles have to be frozen obliquely and without any cap.
• The liquid/media may be frozen in the bottles with cap, but not tightened, until the temperature reaches -10°C. Then, the cap should be removed and the freezing process can be continued until it attains -70°C.
• While defreezing it should be ensured that the process is very slow with a maximum of 100k(Kelvin). ( It is essential to note that the defreezing does not exceed 100k, otherwise there are chances of bottle breaking probably with a blast.)
• Duran Laboratory Bottles should not be used for applications where pressure is involved. For applications involving pressure use only Duran Pressure Bottle of Capacity – 1000 ML – Catalogue Number 2181054.

CAUTION

                 Laboratory Bottles which require Tamper Proof Caps should be closed only when the contents have to be finally sealed in the bottles. If an empty bottle is closed with a tamper proof cap, then it will not be possible to remove the cap without breaking the seal, hence rendering the cap unusable as tamperproof.

DURAN® Laboratory Bottles now with Batch Certificates

Increasing requirements and standards in terms of quality assurance as well as the retraceability of primary packaging and auxiliary materials (EN-ISO 9000/8402, GMP,EM 178/2002) are becoming more and more significant. To meet these requirements, all SCHOTT DURAN® Laboratory Bottles are now marked with a “Retrace Code”.
 
The 8-digit batch code allows the bottles to be retraced to the point of production and the matching batch. The retrace Code is a contribution to a continuous documentation within the user’s quality management system and it is therefore particularly important in the areas of medicine, the pharmaceutical and food industries.
 
 By using this “Retrace Code” and the corresponding SCHOTT item number, every user can easily, conveniently and at any time retrieve a batch and quality certificate via internet. Besides the production date, the certificate also provides information on conformity with standards and USP/EP.