Ultrasonic Baths

An ultrasonic cleaner is a cleaning device that uses ultrasound (usually from 20–400 kHz) and an appropriate cleaning solvent (sometimes ordinary tap water) to clean delicate items. The ultrasound can be used with just water, but use of a solvent appropriate for the item to be cleaned and the soiling enhances the effect. Cleaning normally lasts between three and six minutes, but can also exceed 20 minutes, depending on the object to be cleaned.

Ultrasonic cleaning penetrates even microscopic openings to provide complete cleaning of the objects treated. This makes it one of the most effective, economical and powerful cleaning methods available. It has applications in laboratories, dental and medical technology, microelectronics, precision engineering, cosmetics, optics and the automotive industry. Ultrasonic cleaners are used to clean many different types of objects, including jewellery, lenses and other optical parts, watches, dental and surgical instruments, tools, coins, fountain pens, golf clubs, window blinds, firearms, musical instruments, industrial parts and electronic equipment. They are used in many jewellery workshops, watchmakers' establishments, and electronic repair workshops               

Modern baths tend to have a heavy duty ultrasonic generator which ensures that the ultrasonic output remains constant, regardless of the bath temperature, fill level and cleaning material. This feature guarantees consistent and reproducible cleaning results. 'Frequency sweeping', a frequency modulation of the ultrasonic output generated, prevents 'standing waves' from being generated and ensures extremely homogeneous energy distribution in the cleaning bath.

 

Ultrasonic cleaning uses Cavitation bubbles induced by high frequency pressure (sound) waves to agitate a liquid. The agitation produces high forces on contaminants adhering to substrates like metals, plastics, glass, rubber, and ceramics. This action also penetrates blind holes, cracks, and recesses. The intention is to thoroughly remove all traces of contamination tightly adhering or embedded onto solid surfaces. Water or other solvents can be used, depending on the type of contamination and the workpiece.

 

There are various ways to test the level of ultrasonic activity within an ultrasonic bath..

 

There are a number of recommended tests for establishing levels of ultrasonic activity in the bath.

The foil test involves suspending a strip of foil into various locations around the tank. The foil should not touch the base of the tank and should be held in position for around 1 minute. It should then be removed and there should be an even distribution of perforations and small holes on the surface of the foil.

Another test requires the use of Brownes soil test strips. These are plastic strips which have been contaminated to simulate the contamination which might affect surgical instruments. After running an ultrasonic cycle the strips should be taken from the bath and all contamination should have been removed.

An ultrasonic energy meter can also be used to test the level of ultrasonic activity within the tank.

For more information on ultrasonic baths visit:-
http://www.prlabs.co.uk/lab-supplies.php?N=ULTRASONIC-BATH-1L-MECH.-TIMER%26HEATER&Id=64514
http://en.wikipedia.org/wiki/Ultrasonic_bath

Titration

Titration, also known as titrimetry, is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte. Since volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the titrant or titrator is prepared as a standard solution. A known concentration and volume of titrant reacts with a solution of analyte or titrand to determine concentration.

Titrator set up

 
The word "titration" comes from the Latin word titulus, meaning inscription or title. The French word titre, also from this origin, means rank.
 

There are several reasons why titration is used in laboratories worldwide:

1. Titration is an established analytical technique
2. It is fast
3. It is a very accurate and precise technique
4. A high degree of automation can be implemented
5. Titration offers a good price/performance ratio compared to more sophisticated techniques
6. It can be used by low-skilled and low-trained operators
7. No need for highly specialised chemical knowledge

Karl Fischer titration: A potentiometric method to analyse trace amounts of water in a substance. A sample is dissolved in methanol, and titrated with Karl Fischer reagent. The reagent contains iodine, which reacts proportionally with water. Thus, the water content can be determined by monitoring the potential of excess iodine.

 

Automated titrators follow a defined sequence of operations. This sequence is basically the same for all different models and brands. This sequence is performed and repeated several times until the endpoint or the equivalence point of the titration reaction is reached (titration cycle).

More complex applications require more steps, for example dispensing of an additional reagent for back titration, dilution of the sample, adjustment of the initial pH value, etc. These steps and the corresponding parameters are defined in the titration methods used by the titrator.


P&R Labpak offer a full range of titration equipment and associated consumables and chemicals such as Hydranal^® reagents.

For more information visit:-
http://en.wikipedia.org/wiki/Titration

Christmas Closure

P&R Labpak closes on Tuesday 24th December 2013 and re-opens on 2nd January 2014. There will be no deliveries during this period.

P&R Labpak would like to take this opportunity now to thank you for your custom this year, and look forward to continuing our relationships in 2014.

We hope you've enjoyed our blog posts over the last year and hope you will continue to read them in future.  If you want us to feature anything or try and answer a question for you then let us know.

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Looking for laboratory consumables, equipment or chemicals?

If you want to find and order laboratory supplies quickly from our website, enter a key word or product code into the search box and we'll help you find it!

P&R Labpak Limited has built its reputation for a commitment to quality and customer care with over 25 years experience serving science across all economic sectors.

We are able to offer a vast range of laboratory apparatus, instruments, equipment, consumables and chemicals from our catalogues. We carry stock at our St Helens site and have electronic access to our main supplier giving us live data on product availability.

This means that you get your goods quickly and efficiently.

If you would like to request a quotation for a particular item or have an enquiry, please click here.

We offer varied and flexible services to our customers. In addition to the many products available through our catalogues, we can also:

• Supply production grades and volumes of chemicals and solvents
• Handle all your chemical waste
• Supply and service your microscopes
• Offer third party procurement
• Supply and install laboratory furniture

We do not limit our range to the products in our catalogues. Simply let us know what you are looking for and we'll do our best to meet your requirements.

P&R Labpak Limited offer a comprehensive single source of laboratory chemicals and reagents. These include general laboratory and analytical reagents, culture media, solvents, buffers, biochemicals, water test kits and many more.

• We can supply chemicals in quantities from milligrams to tonnes
• We can supply virtually any chemical you require using our extensive research capabilities
• All chemicals are rigorously tested to meet the critical standards demanded by our customers
• The BDH Prolabo and Merck range of chemicals that we supply are synonymous with quality throughout the world and certificates of analysis can be supplied at no extra charge.
  
• We also sell a wide range of P&R Labpak Limited brand solutions and standards. We can manufacture to order so reaction to customer demand is rapid. The P&R Labpak Limited brand extends to a vast range of general purpose and AR grade chemicals.

P&R Labpak Limited offers a wide range of equipment for all your laboratory requirements from autoclaves and balances to vacuum pumps and water purification systems. A selection of products from key suppliers are shown below but please request our catalogue for details of the full ranges available.

We are able to offer technical assistance and additional product information to help you choose the correct piece of equipment. Given your requirements we will endeavour to source the best goods and put together the products and services appropriate for you at the right price.

Product Range

Sterilin disposable plastics. Pyrex, Quickfit and MBL laboratory glassware.and Azlon reusable plasticware.

The Bibby Scientific range of equipment covering the Stuart and Jenway brands. Items include pH meters, spectrophotometers, fluorimeters, hotplates and stirrers to name a few.

Sartorius weighing technology is available from P&R Labpak Limited with a range of precision and analytical balances together with a wide range of Hettich centrifuges.

The A&D range encompasses a range of balances covering analytical, precision and industrial requirements.

The Mettler range comprises a range of laboratory equipment including a range of precision & analytical balances, ph meters and instruments for density determination.

We can supply many other branded items of laboratory equipment.

 

Visit http://www.prlabs.co.uk to use our online webshop.  Terms and conditions apply.  Call 0870 034 2055 for more details or to enquire about the webshop or anything else.

How to choose a Laboratory Oven.

Laboratory Ovens.

There are many models and styles of laboratory ovens available. Looking through laboratory catalogues it is sometimes difficult to decide where to begin in choosing a lab oven.

When choosing a laboratory oven you should consider the following:

Temperature-It’s best to choose an oven with a maximum temperature rating greater than your maximum temperature requirements. This will allow the set temperature to be maintained more accurately.

Laboratory Oven

Circulation-Ovens use either gravity convection or mechanical draft (forced draft – ie fan) to heat the oven contents. It is possible for gravity convection ovens to have "cold" and/or "hot" spots as the air inside the oven can become stagnant. It depends on what you are doing as to whether it is critical to have a very uniform temperature.  Circulation depends on the difference in the air temperature within the oven. Typically, mechanical or forced draft ovens have fans that induce air flow through the oven to produce even heating.

Size-Sample container size, the number of samples and personal preference are important factors in properly sizing an oven. An oven with extra interior capacity might be nice to have but oversized ovens require more energy to heat, special electrical power and can take up valuable space in the laboratory. A number of smaller ovens rather than one large oven may be a good choice. Nevertheless, large ovens do have a place in the high-production laboratory or when large sample sizes are needed.

Large capacity Lab oven

Controls-Digital controls as opposed to analogue controls allow the operator to easily set the temperature requirements and display the actual oven temperature.

Location-Choose your oven location carefully. Proper location can be a great time saver. Scales, balances and ovens are the most frequently used items in a lab. Placing them in the flow path of samples in the laboratory can save time and labour. Ovens are often placed along a wall, with the scales and balances located beside the oven or on a work table in front of the oven. Be sure to consider any exhaust requirements as well.

Drying Cabinet

Motor protection- Should it be explosion-proof for volatile samples?

Mounting-Should it be a table top or floor mount model?

Visit http://www.prlabs.co.uk/news/article.php?Id=203 for more information on lab ovens.

Weighing the right way.

Weighing the right way

The link above is for a pdf booklet from Mettler Toledo.  It is a detailed guide to getting the best results from your balance. What you should do and what you shouldn't.

Definitely worth a read!


Proper weighing with Laboratory Balances....

Laboratory Equipment

P&R Labpak offer a full range of laboratory equipment from most of the major brands to suit all budgets.  We are able to offer technical help and advice to help you choose the correct item or to help you meet your budgetary requirements.

We sell items from autoclaves & balances through to glassware washing machines and water baths.  Whatever you need we can help.  We can also source products that are not within our catalogue or are 'non-standard'.

For more information on laboratory equipment please click on the link below or contact us in the usual way.

Laboratory Equipment

Presspak Newsletter - New Stuart Undergrad stirrer/hotplates

P&R Labpak's new Presspak Newsletter is out!

The market leading range of Stuart hotplate/stirrers has been redesigned.

The new Undergrad range is stylish and economical and offers a number of novel features.

Get 10% discount during May and June by quoting STUART10 and referring to our newsletter. Offer applies to the SCT1 additional temperature controller as well.

Don't miss out on these new models at these great prices!

Click to download the newsletter now!

Our new 2012-2014 catalogue is now available!! Copies are being distributed to customers but if you haven't got yours yet or would like a copy please get in touch.

The new catalogue features a wealth of products catering for all budgets laid out in application based chapters, bringing all of your needs together in one place.

Don't miss out!

All your laboratory consumables, laboratory equipment and more in one place.