FRITSCH Rotary Cone Sample Divider - LABORETTE 27
With today's modern particle characterization instruments it is possible to achieve levels of precision that were previously unheard of. Trace analysis with verification limits in the parts per million (p.p.m) and parts per billion (p.p.b.) are now standard.
However, the overall error in analysis that comprises the measurement of the analytical instrument in addition to the sampling, is often overlooked. This means that if an error of 15% is made while taking the sample, this will never disappear irrespective of the instrument's precision.
This error in sampling becomes even larger when an analysis quantity less than 200 mg is necessary and the quantity of the original sample is available to the lab is, for instance, 2,000 g. This makes it necessary to divide to total quantity in a representative sub-quantity. The aliquot must be representative and possess both the same chemical and physical properties and the entire quantity.
This ideal, representative sample can be easily obtained with the Rotary Cone Sample Divider LABORETTE 27 from FRITSCH. Its design is based on the combination of several dividing processes in a single instrument. The sample is fed through a funnel before reaching a dividing cone that has a shape that allows for the coning and quartering of the sample.
The sample material, when against the cone's surface, accelerates outward through the rotation of the whole system and divided by guide channels into 8, 10, or 30 separate material flows which is determined by the dividing head being used. Because of the dividing head's rotation, the dividing steps increases by up to 2600 per minute. The final reduced sample is comprised of the extremely large number of individual samples.
When the sample is introduced slowly and uniformly, the resulting sample division will be more accurate. This is the reason we recommend using the FRITSCH Vibratory Feeder LABORETTE 24. With the rotary sample dividers from other manufacturers, the introduction of the sample takes place eccentrically into individual sample bottles. Unfortunately, this process often results in systematic errors. When a feeder channel is used, the sample's segregation often occurs in the channel, resulting is a reduction of dividing accuracy. The LABORETTE 27 can reduce this error by introducing the sample over a central dividing cone. Because of the cone's rotation, the material is spread radially and evenly over 360°.
Of course, both the cleaning and handling of the sample divider is also important. The product also has a dividing head that can be easily removed from its drive shaft for cleaning with a brush, or you can remove it with compressed air. It can also be rinsed with water or washed in a dishwasher or ultrasonic bath.
The dividing head is offered in a variety of versions. These different versions allow for division ratios of 1:8 (in 500 ml or 250 ml bottles, i.e. a maximum of 4 litre sample), 1:10 (in 250 ml bottles, 2.5 litre sample) or 1:30 (15 ml, 20 ml or 30 ml bottles, maximum 300 ml sample). Additionally, these individual dividing heads are offer in both POM plastic and aluminium. The dividing head is also available in 1:30 with PTFE coating.
Good sample preparation is critical in order to fully benefit from the precision of today's modern analytical devices. Every modern analytical laboratory should take advantage of the FRITSCH Rotary Cone Sample Divider LABORETTE 27. When the high investment costs of analytical instruments are considered, it is easy to justify the cost of this product.
Date added: 2015-05-25 11:08:08