Caesium

Cæsium is a soft, silvery-gold alkali metal with the symbol Cs and atomic number 55.

It has a melting point of 28°C (82°F), which means it will be liquid on a warm summer day, and revert to a solid later that night after the ambient temperature cools. Cæsium is just one of five elemental metals that are liquids at or near room temperature.

Its name comes from the Latin word for sky-blue because when burned, cæsium turns the flame a lovely blue colour.

Since the 1990s, the largest application of the element has been as caesium formate for drilling fluids, but it has a range of applications in the production of electricity, in electronics, and in chemistry. The radioactive isotope caesium-137 has a half-life of about 30 years and is used in medical applications, industrial gauges, and hydrology. Nonradioactive caesium compounds are only mildly toxic, but the pure metal's tendency to react explosively with water means that caesium is considered a hazardous material, and the radioisotopes present a significant health and ecological hazard in the environment.

Caesium is also know for its use in atomic clocks and use the electromagnetic transitions in the hyperfine structure of caesium-133 atoms as a reference point. The first accurate caesium clock was built by Louis Essen in 1955 at the National Physical Laboratory in the UK. 

These clocks measure frequency with an error of 2 to 3 parts in 10¹⁴, which corresponding to an accuracy of 2 nanoseconds per day, or one second in 1.4 million years. The latest versions are more accurate than 1 part in 10¹⁵, about 1 second in 20 million years.  The Caesium standard is the primary standard for standards-compliant time and frequency measurements. Caesium clocks regulate the timing of cell phone networks and the Internet.

For more information visit
https://en.wikipedia.org/wiki/Caesium
https://www.theguardian.com/science/grrlscientist/2012/mar/23/1

Timers!

Many laboratories use timers for various purposes - timing heating applications, cooling periods, cycling events, enzyme tests, viscosity measurements, animal studies, and other timed lab tests etc..

When choosing the best timer or stopwatch for your lab you should take into consideration ease-of-programming as well as ease-of-use. You can select from a variety of models based on timing modes, timing capacities, count directions, resolution, and accuracy. General -purpose timers can time the length of events with an alarm function for your laboratory. They are generally available in several styles - single channel, multi channel, count up, count down etc..

VWR Traceable Timers

Labs these days need to have traceable results and the introduction of Traceable® timers has proved popular initially in America and more recently in Europe.
 
P&R Labpak are able to offer VWR Brand Traceable® timers and also some traceable tools.

Items are individually serialised, calibrated and certified, traceable to NIST.

Various timers available including multi coloured ones, jumbo versions, four channel, flashing LED, Extra-extra LOUD ones for use in high-noise areas, waterproof and steamproof ideal for use in wash-down areas.  Also available are traceable® thermometer/clock/humidity monitor, calendar clock, wall clock models.

Finally there are some traceable® tools such as Digital Calipers, SpatulaBalance and Counter-Pens.  Traceable® products are provided with a Traceable® Calibration Certificate from an ISO 17025 calibration laboratory.

 

 

Visit http://www.prlabs.co.uk/news/article.php?Id=245 to download the brochure and find out more.