Looking for Fluorescent Lamps, HPLC Detectors, Infrared Heaters, PCI Products, Varistors or Welding Accessories?

Find them on GlobalSpec!

  Fluorescent Lamps

Fluorescent lamps are high efficiency lamps utilizing an electrical discharge through low-pressure mercury vapor to produce ultraviolet (UV) energy. The UV excites phosphor materials applied as a thin layer on the inside of a glass tube which makes up the structure of the lamp. The phosphors transform the UV to visible light. You will find contact information for 47 manufacturers in this category.
Click here to search for Fluorescent Lamps by Spec.

  HPLC Detectors

Optical detectors are used most frequently in liquid chromatographic systems. These detectors pass a beam of light through the flowing column effluent as it passes through a low volume flow-cell. The variations in light intensity caused by UV absorption, fluorescence emission, or change in refractive index (or other detection) from the sample components passing through the cell, are monitored as changes in the output voltage. These voltage changes are recorded on a strip chart recorder and can be fed into an integrator or computer to provide retention time and peak area data. You will find contact information for 38 manufacturers in this category.
Click here to search for HPLC Detectors by Spec.

  Infrared Heaters

Infrared heaters use a reflective shield to direct radiant heat onto a heated surface. Common types of infrared heaters include metal-sheathed tubular heaters, quartz tubes, quartz lamps, gas fired catalytic, flat-faced panels and ceramic emitters. Infrared flat panel heaters are used to heat objects via radiant heat transfer. Infrared heater elements are replacement heater elements used with radiant flat panel heaters and radiant reflective heaters. Replacement elements are of the same types and configurations used in full heating systems. Infrared reflective process heaters use a reflective shield to direct radiant heat onto a heated surface. Many infrared reflective process heaters are so precise that heat can be directed to pinpoint locations. Infrared reflective process heaters are used in food service, as well as in a variety of other applications. You will find contact information for 69 manufacturers in this category.
Click here to search for Infrared Heaters by Spec.

  PCI Products

PCI (Peripheral Component Interconnect) is a local bus standard developed by Intel Corporation in 1993. Most modern PCs include a PCI bus in addition to a more general ISA expansion bus. PCI is also used on some versions of the Macintosh computer. PCI is a 64-bit bus, though it is usually implemented as a 32-bit bus. It can run at clock speeds of 33 or 66 MHz. At 32 bits and 33 MHz, it yields a throughput rate of 133 MBps. You will find contact information for 87 manufacturers in this category.
Click here to search for PCI Products by Spec.

  Varistors

Varistors are nonlinear two-electrode semiconductor voltage-dependant resistors. The current in a varistor is proportional to applied voltage raised to a power. These devices are normally made of zinc oxide. Upon application of a high voltage pulse (such as lighting) they conduct a large current, thereby absorbing the pulse energy in the bulk of the material with only a relatively small increase in voltage, thereby protecting the circuit. You will find contact information for 34 manufacturers in this category.
Click here to search for Varistors by Spec.

  Welding Accessories

Welding accessories include many products used in the welding and joining process. Torches, nozzles, regulators, safety devices and protective clothing, sensors, and positioners are examples of the many devices used in the welding process. You will find contact information for 172 manufacturers in this category.
Click here to search for Welding Accessories by Spec.

Comtrol Corporation

*** NEW! RocketModem III™ Multimodem Card *** Time-saving, cost-effective solution for remote access or broadcast faxing. Easily add up to 32 56K V.90 modems to your PC server via PCI-bus slots. PCI 3.3 / PCI 5.0 / PCI-X. Click here for more information on the RocketModem III™ Multimodem Card. *** NEW! RocketPort® USB Serial Hub II *** Quickly connect multiple serial devices to a USB port! Four RS-232, DB9 connections. Click here for more information on the RocketPort® USB Serial Hub II. Learn more about Comtrol Corporation by clicking here or browse their online catalog here.

Technical Library Spotlight: "Why Capacitors Fail"

"Paper and plastic film capacitors are subject to two classic failure modes: opens or shorts. Included in these categories are intermittent opens, shorts or high resistance shorts. In addition to these failures, capacitors may fail due to capacitance drift, instability with temperature, high dissipation factor or low insulation resistance.

Failures can be the result of electrical, mechanical, or environmental overstress, "wear-out" due to dielectric degradation during operation, or manufacturing defects."

Topics covered in this article include:

• Dielectric Breakdown (Shorts)
• Open Capacitors
• Environmental Considerations
• Service Life
• Capacitance
• Insulation Resistance
• Dissipation Factor
• Dielectric Strength
• Sealing
• Vibration, Acceleration & Shock
• Barometric Pressure
• Radiation
• Failure Rate Determination

Click here to read "Why Capacitors Fail," submitted by Electrocube and Seacor Products and Services.

The article is listed in the Electronic Components section of GlobalSpec's Technical Library.

The Challenge - Left-hand Threaded Light Bulbs...

The situation presented in the last edition of the newsletter was: What were light bulbs with left-hand threads made for, and why were they made this way?

Answer: Light bulbs with left-handed threads were originally made for use in public places, such as on trains and subways. The intent was to curtail theft – as they were useless in the home, no one would steal more than a few before realizing the bulbs wouldn't work with a regular base. These bulbs can still be purchased; they fall under the classification of specialty bulbs.

Here's a sample of your responses...

"Light bulbs with left-hand threads were used on New York City subway cars. There were made this way because they had a problem of the light bulbs getting stolen by the passengers. The passengers were stealing them to use them at home. Changing to left-hand threads made the light bulbs worthless to steal because nobody had left-hand threaded bulb sockets at home."

"Light bulbs with left-hand threads were made for use in public places to deter thieves, because they would not fit in residential lighting fixtures."

"Left-hand bulbs are often used in temporary lighting strings at construction sites. Left-hand threaded bulbs do not fit in normal Edison-based sockets found in most incandescent fixtures, so therefore no one would want to steal them."

"The reason left-hand thread bulbs are made is quite simple: people won't steal what they can't use."

"Left-hand threaded bulbs are produced for use in public places. This is to deter theft, since one cannot use them in standard household fixtures. Left-hand bulbs are still available... make the perfect gift!"

"The reason for light bulbs with L-hand threads is a safety concern. On rotating equipment that is spinning in a clockwise direction, L-hand threads are necessary so that centrifugal force is directed in the tightening direction rather than loosening, thus preventing the bulb from becoming a flying projectile and a bonanza for personal injury lawyers."

"You can still buy left-handed light bulbs for the purpose of theft prevention (New York’s subway system is one such client), but I seem to remember something about Tesla’s fight with Edison over DC vs. AC current having something to do with the evolution of right vs. left-hand bulb threads. (This is only a vague, semi-recollected memory of something from long ago, and has no scientific validity.)"

"Construction sites so people would not steal them. I think this goes along with the little boy on Art Linkletter who, when asked what his father did for a living, said, "My father makes light bulbs and toilet paper." When asked how he knew this, the boy responded, 'That's all he brings home from work.'"

New Question: There's new reason to dread stepping on the bathroom scale - some models now report your body fat as well as weight. How do these scales work?

"The Challenge" is presented for a little fun. If you have a teaser that you'd like to submit, please e-mail the question and answer to: cchestara@globalspec.com. (The more difficult the challenge, the better!)

Find Video Equipment on GlobalSpec

Video Equipment is used for the transfer, routing, and storage of analog and digital video imaging, including recorders, monitors, and servers. Searchable categories within Video Equipment include:

• Digital Video Recorders – record and store video camera output in digital form on disk.
• Multi-input Display Processors – combine multiple signals from real-time video and computer inputs on a single high-resolution monitor projection.
• Multi-screen Display Controllers – used to control and to project multiple images on the same screen.
• Scan Converters – transform computer-video signals into signals that are compatible with television.
• Video Cables – are used for the transmission of video signals including monochrome, composite and component color video signals.
• Video Cassette Recorders (VCR) – Industrial video cassette recorders (VCRs) receive video input and capture the data onto analog or digital videotape. This does not include consumer grade products.
• Video Monitors – display video images from cameras and recorders, often using cathode ray tube (CRT) technology.
• Video Multiplexers – handle several video signals simultaneously for programmable event monitoring, display, and recording.
• Video Processor Boards – used to process video, medical imaging, automated optical inspection, and other related activities. These boards can be fitted from one DSP unit to thousand in order to increase the computing power of the board.
• Video Servers – enable distribution of video signals over networks including local area networks (LANs) and the Internet.
• Video Switchers – control video display sequences for multiple camera systems.

• ARC Systems, Inc.
• Central Electropolishing Co., Inc.
• Chicago Case Company
• Chromalox
• Com-Ten Industries
• Delfasco
• EaglePicher Commercial Power Solutions
• EIS Fabrico

• GM Nameplate
• Jade Corporation
• Mayr Corporation
• Milwaukee Electronics Corporation (MEC) Northwest
• MouseCart
• MSI Engineering

• Praher Valves Inc.
• Rockwell Automation – Dodge
• Rockwell Automation – Reliance Electric
• SAB Associated Wire Products
• Texas Nameplate Co., Inc.
• Thunder Scientific Corporation
• United Plastic Components Inc.

Need to Change Your E-mail or Other Contact Information in GlobalSpec?

Will your e-mail address be changing? Or maybe you're working for a new company, have a new mailing address, or want to change your password? It's very easy to update your profile to include your new information. Simply click on My GlobalSpec, located on the right-side of the site navigation bar (and accessible from any page on the GlobalSpec site). On the right-side of your My GlobalSpec page, you will see the My Profile box; contained in the box are links to Edit Your Profile or Change Your Password. Just type in your new information and click on the Submit button. It's as easy as that!

If you have information you want to change, connect to My GlobalSpec now.

Also, the My GlobalSpec page is where you can also view the information stored in your My Parts List, My Saved Searches, and My Last 10 Searches.

GlobalSpec's Technical Library

Visit the GlobalSpec Technical Library for easy access to application notes, articles, tutorials and links – you can search by keyword or browse categories, some of which include:

• Computer Peripherals
• Displacement Sensing
• Fiber Optics
• Gas Handling Equipment
• Inspection Tools and Instruments
• Multimeters and Electrical Test Meters
• Power Generation and Storage
• Pumps
• Spectrometers and Analytical Photometers
• Vacuum Equipment