Battery Sizes

The most commonly available batteries are cylindrical cell batteries.

AA - also known as penlights, are one of the most common types of battery in the marketplace. They were introduced in 1907 and are 5cm (50mm) in height.

AAA - are known as microlights. They are 4.45cm in height and slimmer than the AAs.

C - (aka MN1400) 5cm by 2.6cm (same height as AA but fatter). Comes in a range of varieties e.g. LR14 (alkaline), and R-14 (carbon zinc). Used for medium drain applications.

D - 6cm tall by 3.42cm wide. This was introduced in 1898 as the first flashlight battery.

Some cameras use specialist battery types.

Keeping up with LED Technology

Read LEDs Magazine

This will help you stay current with new terminology in the LED market such as:

SSL - Solid State Lighting
NGL - Next Generation Luminaire
Luminaire - another word for a light fitting or fixture

What is a Multifaceted Reflector Light Bulb?

Multifaceted reflector (MR) is a reflector housing format for halogen as well as some LED bulbs. They are designated as MRXX where the XX represents an eight of an inch - so MR16 means 2 inches, MR8 is one inch. The MR16 was first sold in 1965. GU10 (G=Glass) is a derivative of the MR housing where the U refers to a U-shaped ceramic base mount.

As with all halogen lamps, MR lamps produce significant heat. For GU10 fittings. you can have GU10 halogen as well as GU10 LED.

IP44 and IP65

IP44 is a common designation for lighting.

4 - as the first digit means anything smaller than 1mm in size will not get through the membrane.
4 - as second digit means resistant to water splashes.

IP44 cannot be used when there is exposure to water jets (but not high pressure or high temperature water jets)

IP65 is the recommended minimum requirement when water jets are involved.

Bulbs without IP markings are by default IP20 which means protection from solid objects but no protection from water.

What is Grout?

Grout is a construction material that can be used to fill voids and seal joints (such as those between tiles). It is generally made up of water, cement, sand. It is applied as a thick emulsion and hardens over time. When mixed and applied correctly it creates a waterproof seal.

Tiling grout is cement based and comes in sanded or unsanded varieties. Sanded contains finely ground silica sand. Unsanded is finer. They can be enhanced by polymers or latex.

Sanded tile grout is cheaper but should not be used when there is a risk of the sand scratching the tile surface, for example glass and certain porcelains.

Grout sealer is a water-based or solvent based sealant applied over dried grout that resists water, oil or acid based contaminants.

PEI Ratings for Tiles

Tiles are classified under the Porcelain Enamel Institute (PEI) ratings system for suitability for fixing in a particular area. PEI Class III is for residential light to moderate traffic. PEI Class IV are for residential floors, moderate traffic areas like bathrooms, halls, kitchens and conservatories. Class V are for all residential floors and medium traffic commercial areas.

Moisture Absorption Rating for Tiles

The American National Standards Institute (ANSI) has developed a rating for moisture absorption for tiles. If moisture penetration is too high, some tiles may crack. Tiles with W.A. Ratings of 0.5% or less are regarded as impervious. 0.5% to 3% is regarded as vitreous.