The United States Postal Service (USPS) is all about getting mail to the right place at the right time, especially at the 2.2 million square foot Morgan Processing and Distribution Center, Manhattan, N.Y., one of the USPS' largest distribution centers.

Bar coded totes of mail travel through the facility on 5-1/2 miles of conveyor. At several points, the totes are scanned and weighed, ensuring the mail is tracked carefully from receiving dock to shipping dock.

Each tote of mail is labeled with a ten-digit bar code. The first five digits indicate the zip code of the mail's destination; the next three indicate the class of the mail; and the final two digits indicate the day of the week the mail should be delivered.

Accuracy is crucial each time the bar code is scanned. Unfortunately, accuracy was compromised by scanners that had a low first-time scan rate after more than a decade of use. Furthermore, the scan heads had been discontinued and were expensive to service. A change was in order, according to USPS technician Noel Moran.

Several factors had to be considered when selecting replacement scanners. Totes move along low-profile conveyors at a high rate of speed. In addition, the bar codes are tough to read because the print quality is poor and the labels are enclosed in a cloudy plastic sleeve.

As a first step last summer, 20 of the facility's 42 scanners were replaced. By replacing just half of the scanners (Microscan Systems, Inc. 800-251-7711 www.microscan.com.), accuracy increased dramatically, according to Moran. "Read performance and productivity improved. The new scanners read 10% more labels than could be read with the old scanners," he notes.

In addition to improving the sortation process, better scanning has been useful for other purposes. There are four locations in the facility where scanned data is collected for statistical planning.

"The data is extracted and sent to a computer where it will then be compiled for statistical reports used in future planning," says Moran.

Since September 11, the facility has been decontaminated twice for anthrax, delaying replacement of the other 22 scanners. However, that job is expected to be completed later this year, maximizing scanner performance at the facility.