Average Rated Life (ARL) of Light Bulb

Average Rated Life (ARL)

Working periods of half of the light bulb of a batch is known as Average Rated Life (ARL) of light bulb. Some times it is called a half – life. It can easily explain in this way; if 1000 bulbs are tested and 500 of its can reached 1000 hours, the Average Rated Life (ARL) is 1000 hours. Some bulbs can light for 100 hours; some are 500 hours, some within 650 hours. But ARL is that period, which half of the light bulb working.

Frequently on and off switches of light bulb reduced the ARL. This is less affected for Incandescent, halogen, and LED bulbs. Fluorescent, Compact Fluorescent (CFL), and HID bulbs are more affected by on/off cycles. Main thing is ARL of a light bulb is longer for once or twice turns on/off than many times turns on/off in a day.

Allen Key: A Revolutionary Tools

Allen Key:

Allen key is the most common and well known brand of hand tools. Especially it is a hex key wrench. This Allen brand is owned by Apex Tool Group.

William G. Allen patented a drawing for making hex socket set screws, in 1910. It was a new concept and avoided the classic square head protrusion. The new design of this safety screw reduced the chances of accident. “Allen wrench” and “Allen Key” these terms comes from Allen brand name and it refers to the “Hex keys”, the generic product category.

Tools - Makes The Way Easy

Types of Tools for Your Work.

Tools	American name	British name	Group
	Open – end Wrench	Open – ended Spanner	Common
	Box – end Wrench	Ring Spanner	Common

Vacuum Evaporation

Vacuum evaporation is a process where atmospheric pressure is reducing for create vapor of any liquid at minimum temperature. It is easily to describe for boiling of water. When atmospheric pressure is reduced, boiling temperature of water also decreased from 100˚C (212˚F) to lower. Standard atmospheric pressure is 1 bar (at Sea level). If you create vacuum for boiling water then it can turns into vapor in room temperature.

The normal boiling point of water is 99.97˚C (211.9˚F) at a 1 atm (101.325 kPa) pressure.  IUPAC (International Union of Pure and Applied Chemistry) recommended standard boiling point of water is 99.61˚C (211.3˚F) at a standard pressure of 100 kPa (1 bar).

Understanding mAH / Ah Battery Rating

In electrochemical system (Like electrical batteries), a SI unit is using frequently, which is Ah (Ampere – Hour) or mAH (milliampere – hour). Flowing of 1 ampere steady current or 3600 C charges for 1 hour is equal to 1 Ah. So, mAh is equal to one-thousandth of an ampere – hour or 3.6 C flowing for 1 hour.

Here,

1C (Coulomb) = 1A × 1s.

So, 1 Ah = 60 × 60 × 1C = 3600C [1 hour = 3600s].

And, 1 mAH = (3600 ÷ 1000) C = 3.6C