How to Choose a Continuous Monitor for Your ESD Control Program – Guest Blog

by Craig Zander, Transforming Technologies

In Craig’s latest Guest Blog for Q Source, he provides tips for how to choose a continuous monitor for your ESD control program

The first step in a quality ESD control program is grounding your personnel. People walking in a facility and performing common tasks generate a static charge. If not grounded, the voltage accumulated through this charging may be transferred to your product and can cause significant or catastrophic damage to electronic devices.

The most common method for grounding people handling electronics is by using a wrist strap and coil cord. The wrist strap and cord transfer any voltage from the person to ground. When a wrist strap system is functioning correctly and worn properly, it is extremely difficult to accumulate more than a few volts on a person, which, in all but the most extreme cases, is not enough to cause damage to devices.

Wrist strap systems should be tested on a regular basis.

If the wrist strap system is malfunctioning or worn improperly, the voltage may continue to grow and accumulate to levels that can damage most electronic devices. Therefore, it is very important that the wrist strap system be tested on a regular basis to assure that it is functioning properly.

There are a number of ways that the wrist strap system can be tested, and the best method depends on the number of employees in the facility, the critical nature of the product (i.e., medical, aerospace, military, high value), and budget.

One of the most common methods for verifying wrist strap performance is the wrist strap/footwear test station. The test station(s) is placed near the entrance to the ESD Protected Area (EPA) and employees test their wrist strap to verify its operation before they are allowed to enter the EPA. The testers have a wide range of capability and costs. Some testers have a simple pass/fail indicator while other testers have digital readouts and data logging capabilities to record the test results for each employee. While these testers meet the requirements of regular testing of the wrist strap, there are a number of potential drawbacks:

• Test Frequency: How often the person goes to the test station varies between companies. Some companies require testing at the beginning of each shift while others test every time the person leaves the work station for breaks. In each case, should the test indicate a failure of the wrist strap, there leaves a question as to when the failure occurred and how much product was handled with the failed strap. For high reliability and value products the customers of this company may want to know the disposition of the product that was handled during the time between tests.


• False Security: When testing a wrist strap at a test station, only the wrist strap, cord, and person are tested at that precise moment. The situation could change once the operator reaches the work station. The operator could adjust the strap after testing, the resistance could increase due to dry skin conditions, or the ground jack at the work station could malfunction. All of these scenarios could lead to high voltage accumulation on the operator that would not be detected by the tester.


• Wasted Time: Depending on the size of the company, there can be a line at the test station of employees waiting to test their wrist straps, effectively delaying the time they spend on productive activities.


• Record Keeping: Most companies require their people to sign-in at the tester and record the results. There are some systems that automatically record and store the results after the employee has swiped their ID badge. Someone in the company still must maintain and review the test records to assure that everything is working as designed, which can be tedious and time-consuming.

To address these drawbacks, many companies are now using continuous monitoring to verify that the wrist straps are functioning correctly. Continuous monitors are located at the work station and provide an audible and visual indication when the wrist strap system malfunctions. Once the operator hears the alarm they do not touch the product until the problem is resolved and the system is functioning correctly. With continuous monitoring systems, you avoid waiting in line for testers, eliminate the extensive record keeping, and you remove doubt that the product may have been handled by an ungrounded operator. There are no more decisions to be made on what to do with product that was handled by ungrounded operators, as there is no longer any time between tests.

There are a few options available today for continuous monitoring. Some monitors will simply verify the operator wrist strap, while others will verify the wrist strap, the work surface ground, and possibly other equipment grounds.

Capacitance/Impedance Monitors

Some continuous monitors use capacitance or impedance to verify that the operator is connected to the system. These systems allow the company to use the standard single-wire wrist strap and coil cord system and are typically the lowest cost option for continuous monitoring. These monitors operate by using a capacitance or impedance circuit to estimate the resistance of the operator wearing the wrist strap. Since the system is not making an actual resistance measurement, these systems can sometimes be fooled by high skin resistance of the operator and may provide false passes.

Dual Conductor Resistance Monitors

Dual conductor resistance monitors use a special wrist strap and coil cord to incorporate the operator in a resistance measurement. Instead of the single conductor wire found on standard wrist straps, this monitor uses a dual-wire coil cord and a wrist strap that has two isolated halves. A voltage is sent down one of the wires and into the wrist strap. When the person is wearing the wrist strap properly, their skin completes the circuit and the signal returns down the second wire to the monitor. This system assures that the operator is electrically connected to ground.

Many companies are now using continuous monitors like Transforming Technologies Ranger Series.

While dual conductor resistance monitors provide the most reliability, they also typically have the highest cost and require special wrist straps. A new series of dual-wire resistance monitors (from Transforming Technologies) are priced closer to the single-wire systems, but provide the reliability of dual wire. The CM1601 Resistance Ranger provides dual wire monitoring for a single operator, and the CM1602 Dual-Wire Resistance Ranger monitors the operator and one work surface ground. Transforming Technologies also offers great options for dual-wire wrist straps and cords that provide both excellent quality and value.

Thanks, Craig, for further educating us on how to develop and maintain a successful ESD control system. We look forward to your future Guest Blogs.



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Don't Mean to Shock Ya, but 3M Static Control is Now SCS

3M Static Control is now SCS. SCS is a brand of Desco Industries, Inc., who purchased 3M's Static Control business on January 2, 2015.

The SCS brand will use the same part numbers, offer the same quality products at the same pricing, and serve their customers by the same people at 3M's existing Sanford, NC facility. SCS offers the same professional-quality static-control products including Air Ionizers, Anti-Fatigue/Floor/Table Mats, ESD-Safe Garments & Safety Gear, Personal Grounding items, Static Shielding Bags, Tapes, Striping & Adhesives, Test & Measurement Equipment, and many more.

At QSource.com, you'll find more than 800 products of the former 3M Static Control in our new SCS Department. If you've regularly ordered a particular 3M part, there is no need to change the part number. Everything remains the same…just a new name.

To purchase SCS products, please visit our SCS page at QSource.com. For further information, you may also contact Q Source by phone (800-966-6020), email, or via our Web site.

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How to Protect Your Manufacturing Plant from the Hazards of Dangerous Chemicals: Guest Blog

Special thanks to our guest blogger, Lenard Cohen, President of Static Solutions

Companies seeking to avoid potential dangers to their workers, the environment, and ESD-sensitive components must consider a number of factors when weighing the benefits of high-quality ESD products and their cost. To help make this choice easier, the most important step should be to educate the engineers and buyers about the possible risks and how they can be avoided.

Education about the potential hazards will help to address the traditional conflicts every company faces:

• The engineer wants to correct or prevent an ESD-caused problem
• The buyer wants to purchase a material that meets functional specifications
• The safety engineer, if there is one, must specify the safest material and focus on avoiding future litigation

The Clean Air Act Regulations & How to Address Them
Some of the aforementioned conflicts were made more challenging many years back when the EPA's Clean Air Act issued regulations to reduce 189 toxins. The affected products fall under both state and federal regulatory agencies (California and Massachusetts being very stringent).

The best way to address these toxins is by focusing on the two most important criteria:

• The information presented in the Material Safety and Data Sheet (MSDS). Learning to read the MSDS is very important (if you don't know how to read one you're missing potentially vital information; such as if a particular product needs special precautions for application or disposal)
• The Volatile Organic Compound (VOC) number for each product. It is important to keep the VOC number as low as possible to prevent contamination

What are the Sources of VOC
VOCs are most commonly found in the following areas:

• Soldering: such as plating, solder, flux, stencil cleaners, and flux-removing solvents. Using lead-free solders (RoHS approved) has gained common acceptance. One of the concerns of using lead-free solder, though, is the higher operating temperatures, the need to use more aggressive solders, and whisker generation. There are exemptions from the EPA's regulations for the defense and hospital industries
• Coatings: including ESD paints, isocyanates and other cross-linking agents, aziridines, ESD floor finishes, strippers, cleaners, and hand lotions
• Materials: like ESD table and floor mats, finger cots, and smocks
• Coalescent agents from floor finishes and free monomers from polymer binders
• Phthalates used in common table floor mats and the chemicals used to clean the mats
• Paraben-containing hand lotions: are not allowed for pregnant women
• Floor finishes: should not have certain chemicals in their formulation, i.e., phthalates (Green formulations, that have undergone testing, are available from reputable sources)
• Strippers: should not contain sodium hydroxide or Diethylene glycol monobutyl ether (DEGBE)
• Table/floor mats: avoid those containing dioctyl phthalates, which are present in vinyls and lower cost rubber mats

Safeguarding Workers from VCMs
Volatile Condensing Materials (VCM) are also potentially harmful to workers, parts, and the environment. Here are the best ways to avoid the dangers:

• Read the MSDS sheet fully
• Call manufacturers and request hard core test data
• Always use proper precautions when handling all ESD products (gloves, eyewear, exhausts)
Remember when using ESD products the aim is to:

• Eliminate or prevent ESD caused failures
• Create a safe environment (and avoid all potential fines)
• Protect the worker (this will avoid any possible law suits)
• Purchase from proven, reputable sources

Educating workers, engineers, and buyers will help to create a safe and compliant workplace and reduce the chance of employee injuries or legal action against the company. For further information about protecting and preparing your company to face dangerous chemical hazards please contact the experts at Q Source.