Q:  What is the greatest static threat to electronics and other materials?

A:  YOU!

The human body can generate the biggest charge of anything likely to come near these devices.

Charge can often build-up on people and reach levels that give uncomfortable shocks, can damage sensitive electronic parts or give fire risks when handling solvents and other flammable materials. Dry air humidity encourages static charge build-up, and under dry external conditions the atmosphere in a building can become even drier. Electrostatic charge build-up can be far worse under these conditions. For example, on a dry day, humans can generate a static field of more than 100 volts by just the slight raising of an arm.  During normal, everyday activities, it is common to generate 6,000 volts or more.

Every Thursday, Transforming Technologies will answer questions concerning all things ESD: static causes, threats,  ESD prevention, best practices and all things static in a feature we call ESD Q&A.  If you have ESD questions that you would like to be answered, email info@transforming-technologies.com  with Q&A in the subject line.

Q:  When does Static Damage occur?

A:  ESD damage can occur to devices at anytime – even after they have been installed on circuit cards.

Damage can occur simply by placing a fingertip too close to a component inside an open computer!  Everyone involved in the handling, installing, test, shipping and storing of electronic devices must take preventative measures against the threat of ESD. Grounding yourself with ESD wrist straps or ESD heel grounders is the first defense against static damage.

ESD damage can cause immediate or “catastrophic” failure of component, or could gradually degrade components and cause a “latent failure”.  Latent failures are much harder to detect and can pass quality control tests in a factory. This maybe why your computer needs to have a motherboard replaced a year after purchase!

Starting Thursday, Transforming Technologies will answer questions concerning all things ESD: static causes, threats,  ESD prevention, best practices and all things static in a feature we call ESD Q&A.  If you have ESD questions that you would like to be answered, email info@transforming-technologies.com  with Q&A in the subject line.

Understand the Decade Scale

How to read a Surface Resistance Meter.

The Decade Scale is shorthand for electrical measurements, displayed in powers of 10

SRM500K – Surface Resistance Meter

and described in “Ohms”. A Surface Resistivity Meter is used to take these electrical measurements on all types of surfaces and materials, and the results are displayed in the Decade Scale.  Most meters will display results using colored LEDs that brighten according to each decade.  These measurements are important in ESD control because this is how to classify a material as Conductive, Dissipative or Insulative.

Ohms are the units used to describe the  measurements of electrical resistance and has a symbol that looks like this “Ω”.  Depending on the value, measurements can be in “kilohms”, or “meg ohms”.  The decade scale can be written in several ways and mean the same:  10⁵ , 10^5, 100 kilohms, or 100megΩ etc. The table below shows all the values important as it pertains to ESD or Static Control:

Decade Scale

10^3      =1 kilohm
10^4      =10 kilohm
10^5      =100 kilohm
3×10^5  =300 kilohm
10^6      =1 meg ohm
3×10^6  =3 meg ohm
10^7      =10 meg ohm
3×10^7  =30 meg ohm
10^8      =100 meg ohm
3×10^8  =300 meg ohm
10^9      =3000 meg ohm
3×10^9  =1000 meg ohm
10^10    =10,000 meg ohm
10^11    =100,000 meg ohm
10^12    =1,000,000 meg ohm

To learn more about the Decade Scale and Surface Resistivity Meters visit Transforming Technologies or call 419-841-9552

Reliable performance of ESD matting and ESD wrist straps is critical for your product’s integrity and reliability. But the hand testing and hand logging of wrist straps and tabletop material performance that is required is a cumbersome, labor-intensive paperwork nightmare. Use of our ESD wrist strap and ESD bench mat monitors continuously verifies the effectiveness of your ESD protected workstation, simultaneously satisfies ISO logging requirements and insures outstanding product quality.

Operators plug their ESD coil cord into the grounding jack of the constant monitor right at their workstation. The constant monitor grounds the wrist strap and simultaneously monitors for faults in the ground path from the strap to the earth ground, including proper contact with the operators skin. A proper working ground path results in the LED on the constant monitor to glow green (indicating GOOD). If a fault is detected, the LED will blink red (indicating FAULT), and the unit will repeatedly beep.

Types of Constant Monitors

Capacitance (or single wire) constant monitors
This type of monitor is simplest and most cost-effective constant monitor. When a person is wearing the single wire wrist strap the monitor detects the person and puts the monitor in the unalarmed state. The monitor circuit detects a person (a conductive object) and its relationship to ground (another conductive object).  View our Capacitance Monitors.

Impedance (or single wire) constant monitors
The impedance monitor uses a detection circuit designed to reduce false alarms and eliminate adjustments. It uses the phase difference between current and voltage to detect changes in impedance of the cord, band and person. A very low AC voltage is used for constant sensing. Any standard wristband and coiled cord can be used.

Resistance (or Dual Wire) constant monitors
This type of monitor is used with a two wire (dual conductor) wrist strap. When a person is wearing a wrist strap, the monitor observes the resistance of the loop, consisting of a wire, a person, a wristband, and a second wire. If any part of the loop should open (become disconnected or have out of limit resistance), the circuit will go into the alarm state. An important feature of the Dual Wire Wrist Strap is that even if one conductor is severed, the operator has reliable path-to-ground with other wire.  View our Resistance Monitors.

Heel Grounders and ESD Protection

Heel grounders discharge static from a person to ground by connecting the person to a grounded walking surface. A conductive ribbon placed inside the wearer’s shoe or sock makes electrical contact with the skin through perspiration. The ribbon is joined to a resistor which limits current should acci-dental exposure to electricity occur. The other end of the resistor is joined to a conductive sole. This sole contacts a grounded ESD floor mat or ESD flooring system. Heel grounders should be worn on both feet to maintain ground contact while walking. UL and OSHA recommends a minimum of 1 megohm resistance to ground (RTG) in order to limit current for safety purposes.

Resistors and Heel Grounders

Heel grounders come with either a 1 megohm or 2 megohm resistor. When one foot is on the ground, a 1 megohm heel grounder gives you an RTG of 1 megohm and a 2 megohm heel grounders results in 2 megohm RTG. But when both feet are on the ground, the sum of the resistors yield a RTG of 1/2 that measurement.

For example:

• When you wear two, 1 megohm heel grounders and have both feet on the floor, your RTG is only 1/2 megohm, NOT 1 megohm!
• If you wear two, 2 megohm heel grounders an have both feet on the ground, your RTG is 1 megohm.
• By wearing two heel grounders with a 2 megohm resistor you are com-plying with UL and OSHA at all times.

What is a Resistor?

A resistor is a component of an electrical circuit that resists the flow of electrical current. A resis-tor has two terminals across which electricity must pass, and is designed to drop the voltage of the current as it flows from one terminal to the next. A resistor is primarily used to create and maintain a known safe current.

Most grounding products have a current limiting resistor and it is most commonly one megohm, rated at least 1/4 watt with a working voltage rating of 250 volts. This ensures that the flowing current will be within safe levels.

Types of Heel Grounders?

Heel Grounders come in a variety of styles:

Cup Style

Made with two reversi-ble soles for longer life span.

Foot Grounder

Provides a more complete path-to-ground due to wider contact area and heel-to-toe coverage.

Disposable

Strip of conductive material is applied to shoe. Economical and perfect for one time use.

Toe Grounder

Ideal for high heels when stan-dard heel grounders won’t fit properly.

Learn more about Transforming Technologies EFM115 Electrostatic Fieldmeter.

Transforming Technologies has long lasting Cup Style ESD Heel Grounders in Color you want and with protection you need!

Call Transforming Technologies at 419-841-9552 or email sales@transforming-technologies.com for a quote today!

Question:  How should ESD jackets be laundered?

ESD jackets come in many shapes and colors, not to mention fabrics, so it can be very difficult to choose the right jacket for your application.  Now you have tried all the samples, haggled with salesmen, and have placed your first order, how do you care for your ESD jackets to ensure long life?

Answer: Wash in cool or cold water (90°F maximum) with any commercially available liquid detergent. Do not bleach. Hang dry or tumble dry on low heat. The carbon-suffused mono-filament nylon is sensitive to heat and should not be ex-posed to laundering heat in excess of 120°F or more.

Transforming Technologies is proud to announce the addition of the 5049 Series ESD Jackets and Lab Coats to our line of ESD Products.

The 5049 Series Garments are constructed with an anti static polyester and cotton fabric blend, making the jackets effective as an ESD control device and extremely comfortable to wear. Superior workmanship provides reliable panel-to-panel continuity of the garment. The 5049 Series Garment maintains consistent continuity readings for up to 100 wash cycles.

The 5049 Series is available in a waist length jacket or a full length lab coat.  The standard sleeve termination is a three snap adjustable fit cuff (ESD knit cuff with snap-to-ground feature is also available).

Features

• Extremely comfortable blend of polyester and cotton fabric
• Waist length jacket or full length lab coat
• Reliable panel to panel continuity

For price and availability on the 5049 Series Garments or for information on any products in Transforming Technologies full line of ESD products, please call 419-841-9552 or email eric@transforming-technologies.com.