Basic Barcode Reading Technology – Scanners, Readers and Wireless

The technology used to read barcodes is relatively simple, but there is little information available for the novice. This is intended to be an introduction to the scanning, processing and presentation of barcode information.

Scanners

A scanner is a device that converts the image of a barcode into electrical pulses. There are four basic ways of doing this: contact wands, active non-contact (AKA laser scanners), and passive non-contact, which can be cameras or linear CCDs (charge coupled devices). All of these devices have similar outputs, strings of electrical pulses that mimic the white/dark and width of the bars. With the exception of cameras, a scanner will always include a light source, either LED or laser.

Wands are the simplest, but have the most limitations. A wand has a light source, focusing lens and a light detector. It has no moving parts, which makes it the most rugged of scanners, but … Read More

The Faucet Handle is Hard to Turn – Repairing a Single Handle Faucet

It often happens to me as a plumber. After I repair a faucet and the homeowner turns the faucet lever for the first time they are amazed. “The faucet turns so easily!” they exclaim. What is amazing to them is not that the faucet works so easily after repairing, but that they had never noticed that it was not working well until it either leaked terribly, or was impossible to move the handle.

Think about it. You walk into the kitchen or bathroom and, as you have done thousands of times before, you reach for the handle of the faucet and turn on the water. Notice anything? Probably not. The water flows; you turn it off and go on your way. Because you use the faucet everyday, what you don’t notice is that gradually the internal parts of the faucet gain a buildup of minerals from the water, and the … Read More