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The Wireless Wrist Strap – Do They Work?

 We Put Them to the Test!  And They FAIL!

The wireless wrist strap has been available for over 10 years.  We have seen them used in the electronics manufacturing and other assembly applications and have received several inquiries about their performance.

In this blog, we test and report on the effectiveness of the wireless wrist strap. Our results indicate wireless wrist straps fail to ground operators or keep operators sufficiently neutral. Read why the wireless wrist strap system results in a potential nightmare of problems and view the hard data that proves they don’t work.

wireless wrists strap

Background: The Wireless Wrist Strap Dream

It would be nice to be able to effectively drain the charge from a person without them tethered to a work station with standard wrist straps or other ground connection.  ESD flooring and footwear is an option, however it can require a significant investment for it to be effective. Hence, the dream of the wireless wrist strap.

So what about the wireless wrist strap?  The advertising says “This compact wrist strap eliminates static without the need for a pesky grounding cord.  This allows you freedom of movement so you can leave your work area without needing to unclamp yourself and lose your anti-static protection.”  It also states that the band “…ensures that you have a much smaller static build-up and dissipates it quickly.”

Wireless Wrist Straps vs. Physics

That all sounds wonderful in theory, unfortunately it does not work as advertised.   Most companies follow the ANSI/ESD S20.20 standards for their ESD Control Programs which requires human body voltage to be less than 100 volts and the wireless wrist strap does not meet the requirements of the standard.

The standard states “All personnel shall be bonded or electrically connected to the grounding/equipotential bonding system when handling ESDS items.” The standard goes on to list the requirement of a resistance between the operator and ground of less than 35 megohms.  This requirement seems quite impossible to meet with the wireless wrist strap.

Corded wrist straps

Resistance to Ground of person wearing a corded wrist strap

wireless-wrist-strap-walking-test

Resistance to Ground of person wearing wireless wrist strap

But what if you are not tied to the industry standard and just want to make sure that you are not generating excessive voltage that could harm electronic devices or assemblies?  The voltage generated and stored on the person is what is important.  So let us conduct another measurement that compares the voltage generated on a person that is a: not grounded, b: grounded through a conventional wrist strap/cord system and c: a person wearing the wireless wrist strap.

The Walking Test

For this test we will use the Warmbier WT5000 walking test instrument.   This instrument measures and records the voltage on a person while walking or simply standing.  To measure the voltage we held the test electrode on the instrument and repeated the six step walking test described in ANSI/ESD STM97.2 – Voltage Measurement in Combination with a Person.

Figure Standard shoes, tile floor, with no wrist strap

Figure 1: Standard shoes, tile floor, with no wrist strap

You see that from Figure 1 that the voltage on the person wearing standard shoes on a tile floor and no wrist strap was greater than -500 volts.   This voltage is well in excess of the damage thresholds for many devices today.    Next we will try the same floor and footwear but the operator will wear a standard wrist strap with coil cord (Figure 2).

Standard shoes, tile floor, wearing corded wrist strap

Figure 2: Standard shoes, tile floor, wearing corded wrist strap

In this case you should notice that the voltage is minimal.   The peak voltage was -1.41 volts and the valley was +0.46 volts.

Finally, we test the same floor and footwear with the wireless wrist strap (Figure 3).

Cordless wrist strap

Figure 3: Wireless wrist strap

The graph in Figure 3 shows that while wearing the wireless wrist strap, voltages of greater than

-100 volts were reached within one second of the test and peak voltages exceeding -500v were reached in less than 10 seconds.

Wireless Wrist Straps are Unacceptable

So in addition to not being electrically bonded to ground, the wireless wrist strap does not prevent charge build-up or decay charge at a rate that is acceptable for handling electronic devices.

It would be nice to be able to handle electronic devices without that bothersome coil cord getting in the way or without having to invest in a flooring and footwear system, however the reality is that a person must be physically and electrically attached to ground to drain charge from their body.

 

Is Your Facility In Need Of ESD Training?

April 25, 2016

 Professional ESD Services

Transforming Technologies provides comprehensive knowledge of electrostatic issues, effective solution-oriented products and outstanding, friendly service.

 Because customer needs periodically include requirements for consultation, training, auditing or verification, we offer Professional ESD Services such as trainings or audits.

Please contact us for more information on our professional services and insure that your static control program is as effective and efficient as possible.

Medivators training31

 General Static Charge Audit

Find out if your facility has static charge in locations that can be harmful to your manufacturing process. The work includes benchmarking of each step of the production line, measuring electric fields and electromagnetic interference caused by electrostatic discharge.  A report is supplied with interpretation of results and assessment of the magnitude of each item found.

Additionally, this service can also include a search for ESD induced transient EMI. This can be important in facilities with lots of computer-driven robotics or automated testing. This type of EMI can disturb microprocessor operations resulting in locked up  or stopped robots, other robotic unexplained behavior or cause good parts to test bad.

Facility Review

Includes a complete static charge audit and detailed review of each step in the manufacturing process. If you prefer, the study can focus on one part of the manufacturing process, for example photolithography.

Where problems are identified a selection of choices of solutions are recommended.  In addition. The study focuses on identifying the steps required to achieve best practices concerning personnel grounding, garments, equipment grounding, hand tools, chairs, work surfaces and automated handling procedures.  A report is supplied with recommended upgrades to the facility intended to improve facility ESD safety.

Ionizer Performance Verification

Find out if the ionizers in the process are working properly and if they are correctly designed in so that they can achieve the results required,  If the ionizers are in need of maintenance or adjustment you will know it.  If ther ionizers can be made to work better, you will receive recommendations.  If the ionizers used are the wrong type or if additional ionizers are required, the report will include these facts.

Ionizer Service: Clean and Calibrate

Corona ionizers collect material from the environment much like a dust precipitator.  That material lowers the efficiency of the ionizer and must be removed.  Also as tools and fixtures are moved in the cleanroom, the balance of the ionizer is effected.  For both of these reasons and because the control circuitry in the ionizer drifts over time, the ionizers require maintenence.

ESD Training

No ESD control program can succeed without the help and cooperation of the production team.  LBL offers a seminar to teach the people manning your production floor about static charge and how the various steps in a control program work.

ESD Issues for the Senior Manager
LBL understands the complex issues that arise from being in charge of quality management and safety. LBL will work with senior management to consolidate best the practices and drive standardization across the organization.

Specific Problem Solving

Wether you are just starting your ESD control program or static discharge has been a main concern for years, LBL understands that every static problem is unique, ranging from the simple to the incredibly complex.  Contact LBL to discuss any issues, big or small that you may have.

Contact us today for more information on ESD professional services

 

3719 King Road
Toledo, OH 43617

(419)841-9552
(419)841-3241 fax
info@transforming-technologies.com

 

 

ESD Mat Selection Guide

April 19, 2016

Introducing Transforming Technologies ESD Mat Selection Guide

Whether it be an ESD Table Mat or an ESD Floor Mat, making the best choice can be difficult. With the help of our ESD Mat Selection Guides, we have condensed all the selection criteria such as material construction, resistance ranges, surface, color, style, or size into two separate charts for your convenience.

Table Mat Selection Guide

ESD Table Mat Selection Guide

Bring your ESD workstation to its optimal level by complementing your table mat surface with any of our ionizers, wristband sets, or constant monitors.

Table Mat Selection Guide - PORTRAIT

Floor Mat Selection Guide

ESD Floor Mat Selection Guide

All of our floor mats may be enhanced by a person(s) use of any of our heel grounders to ensure maximum groundability.

For price and availability on table and/or floor matting, or for information on any products in Transforming Technologies full line of ESD products, please call 419-841-9552 or email info@transforming-technologies.com.

 

ESD Garments and Static Control

March 25, 2016

ESD Garments and Static Control

ESD Jackets

ESD jackets, also commonly known as ESD smocks, ESD lab coats or ESD garments, offer protection from electrostatic fields generated by clothing on the user’s body. ESD jackets are worn where ever static damage is a concern. ESD jackets are designed to be antistatic and low tribocharging because they constructed out of polyester or cotton (or a blend of both) impregnated with a grid of woven conductive fibers. The grid creates a “Faraday Cage” effect around the body of the operator that shields charges generated from the operators clothing from damaging ESD sensitive devices.

ESD Jackets as part of a complete ESD program.

ESD jackets are the most visible sign of ESD protection and facilities that mandate ESD garments demonstrates a commitment ESD protection. ESD jackets are a recommended addition to a program that already includes typical grounding measures, such as wrist straps and heel grounders. This is because of the potential hazard of the operator’s clothing. The ESD TR20.20-2008 states: “While a person may be grounded using a wrist strap or other grounding methods, that does not mean that insulative clothing fabrics can dissipate a charge to that person’s skin and then to ground. Personnel clothing usually is electrically separate or isolated from the body.”

Groundable Static Control Garments Systems

ESD jackets can also be used to ground personal. If the fabric of the jacket is conductive enough, a person can be grounded through a jacket if it is connected to ground with a coil cord. This is called a “Groundable Static Control Garment System”. This jackets must “provide a resistance of less than 35 megohms from the person to the groundable point of the garment.”[ESD TR20.20-2008 section 5.3.13 Garments]

Styles of ESD Garments

ESD Garments come in many shapes and sizes. Typical distinctions are collar type, fabric composition, sleeve terminations and lengths. Collar options typically include lapel, v-neck or military style. Sleeve terminations are either a three snap cuff that adjusts for a proper fit or an ESD cuff that allows for hands free grounding. There are three lengths of jackets, waist length, 3/4ths and full length. Fabrics composition will vary by manufacture but are typically a polyester fabric or a cotton polyester blend with carbon. Your choice of fabric will be determined by operator comfort and ESD performance. You may choose a lightweight polyester for warmer climates or a cotton polyester blend for cooler climates.

Cleaning of ESD lab coats

The proper method to clean a lab coat is to wash the garment in cool or warm water, tumble dry with low heat or hang dry. Do not bleach your ESD lab coats! Make sure you only use non-ionic softeners and detergents when laundering.

View Transforming Technologies’s line of ESD Jackets.

 

New Product Announcement: The SRM330 Lightweight Travel Surface Resistance Meter Kit

March 10, 2016

The SRM330 Lightweight Travel Surface Resistance Meter Kit

The SRM330 Surface Resistance Meter is the ultimate travel kit for testing materials for electrical re-sistivity/resistance according to EOS/ESD, CECC, ANSI, ASTM test procedures. The 9V battery powered SRM330 is equipped with built-in parallel electrodes for quick surface resistance measurements (table matting, floor matting, etc.) and includes two lightweight “travel” electrodes that eliminate the cumbersome weight of standard kits. When pressed, the travel electrodes simulate the 5lbs of pressure necessary to measure resistance point-to-point (RPP) or resistance-to-ground (RTG).

SRM330-surface-resistance-meter-full-kit

Features include:

  • Easy-to-read color coded readout screen
  • Two lightweight travel electrodes
  • Built in resistivity probes
  • Automatic test voltage selector
  • Carrying case

travel-probes

The SRM330 meets periodic test requirements per Compliance Verification ESD TR53 and conforms to ANSI/EOS/ESD (S4.1, S7.1, S12.1, S2.1).

For price and availability on the Ranger series constant monitors or for information on any products in Transforming Technologies full line of ESD products, please call 419-841-9552 or email info@transforming-technologies.com.

 

Introducing Transforming Technologies Resistance Ranger Constant Monitors

February 29, 2016

Resistance Ranger Dual Wire Constant Monitors

The Resistance Ranger Constant Monitors are an accurate and cost effective system to ensure that an ESD workstation station is grounded. The system continually monitors the resistance levels of wrist strap sets and alarm to indicate a failure.  The system uses superior dual wire wrist straps that provide two paths-to-ground to ensure ESD protection. The Rangers can also monitor the ground connection of the ESD worksurfaces and grounded tools.  All three models have conductive cases and use an ultra-low voltage sensing current. The Resistance Rangers are designed for use in the most sensitive environments and processes.

 

Three Models:       


RangerOneâ„¢ – p/n CM1601:   
This model is simplest and most economical constant monitor. It monitors the resistance of 1 person/wrist strap. Also provides a second unmonitored ground jack.

CM1601-resistance-ranger

RangerTwoâ„¢ – p/n CM1602:   
This model monitors the resistance level of 1 person/wrist strap and the worksurface ground. Also provides a second unmonitored ground jack.

CM1602-resistance-ranger(2)

Rangerâ„¢ – p/n CM1600:   
Ranger is the premiere work station grounding system available. The Ranger monitors two wrist bands, two work surfaces, and two auxiliary grounds simultaneously. Also provides two additional unmonitored ground jacks .The Ranger has an output to hookup to an external alarm. The monitor is enclosed in a stainless steel conductive case.

CM1600

Calibration
The Ranger Series is factory calibrated and does not require annual recalibration.  It is recommended to verify the monitors are in proper working order with the CM2015PV periodic verification unit.

Accessories
CyclopsTM Operator Presence Check – CMREMOTE-IR
The Cyclops is an infrared sensor that causes the monitor to alarm when an operator approaches the workstation without connecting their wrist strap. The alarm continues until compliance is achieved.

CP3000 Wrist Strap Parking Station
Provides a jack that will allow an operator to disconnect and leave the dual conductor cord at the workstation without the wrist strap monitoring system alarm sounding. For use with mono plug coil cords.

Superior Technology
Resistance based monitoring is the only true wrist strap monitoring technology available.  Single wire systems simply detect that a person is wearing a wrist strap and put the monitor into an unalarmed state.  Resistance monitors actually measure the resistance of the wrist strap in combination with the person and alarm if the product exceeds preset levels. This accurate measurement ensures reliability.

Compatible Wrist Straps
WB2800 Series Two Snap, Dual Wire Wrist Bands
WB2695 Series One Snaps Dual Wire Wrist Bands
WB5000 Series Mono Plug Dual Wire Metal Wrist Bands
WB7000 Series Mono Plug Dual Wire Fabric Wrist Bands
*Most Standard Dual Wire Wrist Band Sets are Compatible with the CM1600, CM1601 and CM1602

For price and availability on the Ranger series constant monitors or for information on any products in Transforming Technologies full line of ESD products, please call 419-841-9552 or email info@transforming-technologies.com.

 

 

New Product Announcement: GrooveSTAT ESD Conductive Floor Runner

February 23, 2016

Transforming Technologies is proud to announce the addition of the GrooveSTAT ESD Conductive Floor Runner to our line of ESD Products.

FM10-grooveSTAT-esd-floor-runner

Transforming Technologies GrooveSTAT Conductive Rubber Matting provides the electrical properties specified by ESDA standards for floor mats. A ribbed emboss provides a non-slip surface that provides excellent traction and allows the mat to be easily cleaned. The ribbed matting is also very resilient, allowing it to stand up to heavy foot traffic while still maintaining its ESD protection. The material also offers moderate chemical resistance. The matting is 1/8″ thick matting is available in 4’x32′ rolls and an assortment of lengths.For use with ESD footwear such as heel grounders and sole grounders.

Meets or exceeds requirements of ANSI ESD-S20.20 and the recommendations of ESD STM7.1

Benefits & Features of the Transforming Technologies GrooveSTAT ESD Conductive Floor Runner:

  • 100% conductive rubber: 10^3-10^5
  • Corrugated v-groove surface allows for a superior traction and can easily be cleaned
  • Available in rolls or an assortment of lengths.

Specifications of the Transforming Technologies conductive GrooveSTAT ESD Conductive Floor Runner:

  • Point-to-point resistance: 10e3-10e5
  • Mats or full rolls for floor runners
  • Meet or exceeds requirements of ANSI ESD-S20.20 and the recommendations of ESD STM7.1

conductive-v-groove-rubber-mat

 

For price and availability on the FM10 GrooveSTAT ESD Conductive Floor Runner or for information on any products in Transforming Technologies full line of ESD products, please call 419-841-9552 or email info@transforming-technologies.com.

Posted in New Product | Comments Off
 

New Product Announcement: ComfortTREAD Diamond Plate Anti-Fatigue Runners

February 9, 2016

Transforming Technologies is proud to announce the addition of the ComfortTREAD Diamond Plate Anti-Fatigue Runner to our line of ESD Products.

ComfortTread-anti-fatigue-floor-runner

ComfortTREAD diamond-plate ESD anti-fatigue mats keep your workers comfortable and your ESD sensitive equipment safe. The 100% conductive rubber mats are embossed with raised diamond-plate treads for superior traction and feature wide beveled borders to promote safety. A fully molded honeycombed cell design absorbs shock and cushions the feet from constant contact with hard surfaces. The mat will not separate, bubble-up, ripple, tear, compress or lose resiliency. Available in interlocking sections which can be quickly dismantled to make moving and cleaning easy. Two FM9E connected creates a 2.5′ x5′ workstation mat or you can pair the two FM9E with any number of FM9C pieces to create a runner in 30” increments. For use with ESD footwear such as heel grounders and sole grounders.

Meets or exceeds requirements of ANSI ESD-S20.20 and the recommendations of ESD STM7.1

Benefits & Features of the Transforming Technologies ComfortTREAD ESD Matting:

  • 100% conductive rubber: 10^3-10^5
  • Diamond-plate treads for superior traction
  • Interlocking sections create a 5’ long work-station mat or runners in 30” increments.
  • Beveled borders for safety

Specifications of the Transforming Technologies conductive ComfortTREAD ESD Matting:

  • Point-to-point resistance: 10e3-10e5
  • Inlocking mats for floor runners
  • Meet or exceeds requirements of ANSI ESD-S20.20 and the recommendations of ESD STM7.1
ComfortTREAD Anti-Fatigue Interlocking Piece

ComfortTREAD Anti-Fatigue Interlocking Piece

ComfortTREAD Anti-Fatigue End Piece

ComfortTREAD Anti-Fatigue End Piece

For price and availability on the FM9 ComfortTREAD Anti-Fatigue Floor Runners or for information on any products in Transforming Technologies full line of ESD products, please call 419-841-9552 or email info@transforming-technologies.com.

 

Comparing AC Ionizers to DC Ionizers

February 8, 2016

Ionizers remove static from surfaces that cannot be grounded. You will find two common types: AC or Alternating Current and DC or Direct Current. This presentation reviews the pros and cons of each technology and will help you decide which ionizer will work best for your application.

For more information, contact Transforming Technologies 419-841-9552.

The difference between DC and AC ionization is the way the emitter points function.  In AC, like the Transforming Technologies Ptec & BFN Ionizers, the same emitter point alternates between releasing positive and negative ions.  This means they inherently have a voltage balance.  This is because if an emitter gets dirty and isn’t functioning, the other emitters are still alternating between positive and negative ions.  This also means that the ions are closer together which makes it more likely for them to recombine. This means normally higher fan speeds are needed to reduce the time between the fan and the surface that needs to be ionized.

DC ionizers have separate emitters for positive and negative ions.  This means that it’s a little more difficult to ensure a low voltage balance and if one emitter stops working, it throws the unit out of balance.  These types of units require a lot more consistent maintenance/monitoring to ensure a good voltage balance.  The benefits are that the emitters are separate so there is less of a chance of recombination of the ions.  This allows the DC units to operate at a lower fan speed which is very beneficial when your components are small or you are in a clean room.

 

Constant Monitor Selection Guide: Impedance Vs. Resistance

August 22, 2015

Download our slide show here: CM2800 Constant Monitor Capabilities 

ESD Constant monitors reduce production costs by eliminating the time spent on testing wrist straps before each shift. Further savings may be realized by reduced ESD damage from broken wrist straps. Transforming Technologies manufactures two types of 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 coil 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 wrist-band, 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

Transforming Technologies Line of Constant Monitors.
Click here for more information.

monitor-selection-guide

 

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