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Deal of the Week – 15% Off ESD Lab Coats!

http://www.charleswater.co.uk/DealWeek.aspx

Check this link weekly for special pricing on overstock items.

Discover deep discounts on high quality Charleswater ESD Control Products.

Save on your regular stocking orders.

Current Deal of the Week

15% Off ESD Lab Coats

ESD Lab Coats

72120 – ESD Lab Coat, Women, X-Small
72121 – ESD Lab Coat, Women, Small
72122 – ESD Lab Coat, Women, Medium
72123 – ESD Lab Coat, Women, Large
72124 – ESD Lab Coat, Women, X-Large
72125 – ESD Lab Coat, Men, Small
72128 – ESD Lab Coat, Men, X-Large
72129 – ESD Lab Coat, Men, XX-Large

  • Comfortable ESD dissipative lab coats are ideal for any production environment in which sensitive items (ESDS) are being handled.
  • The coats offer ESD protection using the principle of the Faraday cage shielding ESDS from electrostatic charges on operator’s clothing.
  • The buttons at the front have an overlap which avoids direct contact with parts.
  • 2 side pockets and 1 breast pocket.
  • International ESD symbol on breast pocket.
  • Coats are CE certified

Use code C101 at checkout. Valid for online orders only.

Buy Now

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Continuous Monitors: What’’s Better – Single-Wire Impedance or Dual-Wire Resistance Monitors?

Dual-Wire Continuous Monitor

Fred Tenzer on Continuous Monitor History and Preference

By Fred Tenzer

First off, both technologies work fine, but one needs to understand the technologies to understand the shortcomings of each. Let me start with the following basic historical information that will make my “preferences” more clear. If you choose to just know the answer, scroll to the bottom, but I believe this information will be very helpful to you in making your decision. All the technologies will also monitor the worksurface ground circuit and while there are some differences, the worksurface part of the monitoring system is NOT discussed below.

History

When people realized that Operator Grounding was the foundation of an ESD Control Program, wristbands and coil cords came into big time use. The first ESD Association Standards meeting was in 1982 and the first standard written produced by the ESD Association was for wrist straps. The weakest part of the system was the coil cord and testing was developed for bending or flex life testing. The minimum flex life was established at 16,000 flex cycles and in the mid-1980’s that was tough to achieve.

Thus, monitoring technology was initially developed to detect initial flex fatigue while it was still in the “intermittent” stage, which is prior to a permanent open being created. Touch testing would almost never detect this “intermittent” failure mode. In addition, if a wrist strap system was touch-tested twice a day and an operator passed at 1:00 PM on Monday and failed at 8:00 AM on Tuesday, all the work that had peen performed at that station after 1:00 PM on Monday would now be suspect and would be a cause for more detailed quality inspections by many companies. Therefore, while discovering an operator grounding problem was good, it was also costly due to increased Quality Control. Thus, monitoring of the “operator ground system” grew in customer desirability and has resulted in technology improvements by some of the manufacturers and inventors of monitoring technology.

Single-Wire Monitoring Technology

Originally, simple “AC capacitance” single-wire monitors were developed. There were many shortcomings of this technology, all stemming from mostly “false negatives” (unit indicating the operator was grounded when he was not) and “false positives” (alarms going off when they shouldn’t). This technology is still around today and is purchased by some because of its low cost, around £25-£35 per operator and a lack of knowledge by the End User. A big plus is being able to use any standard single-wire wrist strap.

Wave Distortion Single Wire Continuous Monitor

The next level in single-wire evolution was “impedance” technology. However, since the capacitance and therefore the impedance of the circuit will also vary with such things as the person’s size, clothing, shoe soles, conductance of the floor, chair, table mat etc. these monitors often have to be adjusted or tuned to a specific installation and operator. Again, there were resulting “false positives” and “false negatives” though this was an improvement over the simple “capacitance” technology. This technology is also still around; the driver is low cost, £30 -£45 per operator.

The top of single-wire monitoring technology is called “Wave Distortion”. What this technology looks at is not the impedance level, but at the waveform generated by the circuit. Current will leak voltage at various points due to the combinations of resistance and capacitive reactance. There is a negligible amount of inductive reactance from the coil cord. By monitoring these “distortions” or phase shifts the Wave Distortion Monitor will determine if the circuit is complete i.e.; the wearer is in the circuit and the total equivalent DC resistance is within specifications given a range of installations. This technology is very reliable, (virtually no “false positives” or “false negatives”) and response time is very fast (<50 ms). In addition, the wrist strap open circuit test voltage is very low at 1.2 volts peak-to-peak @ 1-2 Micro Amps. Thus, a very low voltage is applied to the operator. The cost for this technology is £75 – £90 per operator.

To continue reading Click Here

Introducing New Conductive Boxes

Ship and store your ESD Sensitive Products
in these Conductive Boxes

Charleswater Rigid Conductive Boxes are marked with the ESD protective symbol. Boxes can be supplied with or without high density (HD) foam for insertion of component leads or low density (FX) foam which acts as a cushioning material meets EN 61340-5-1 Table 4 Packaging required range for conductive packaging.

  • Made of conductive polypropylene;
    Rs, Rv: 1 x 10E2 < 1 x 10E5 ohms
    per IEC 61340-2-3
  • Strong box with integrally hinged lid
  • Provide good ESD and mechanical protection
Item Description Price
Box Configuration – No Foam
71240 Rigid Conductive Box, 35 x 35 x 11mm, Empty $ 1.00
71242 Rigid Conductive Box, 75 x 51 x 14mm, Empty $ 2.50
71244 Rigid Conductive Box, 90 x 64 x 16mm, Empty $ 1.66
71246 Rigid Conductive Box, 108 x 83 x 13mm, Empty $ 3.00
71249 Rigid Conductive Box, 230 x 128 x 20mm, Empty $ 5.45
71251 Rigid Conductive Box, 230 x 128 x 30mm, Empty $ 5.00
71253 Rigid Conductive Box, 230 x 128 x 40mm, Empty $ 5.50
Box Configuration – Foam in Base
71241 Rigid Conductive Box, 35 x 35 x 11mm, 6mm HD in Base Only $ 2.16
Box Configuration – Foam in Base and Lid
71243 Rigid Conductive Box, 75 x 51 x 14mm, 6mm HD in Base/FX in Lid $ 2.78
71245 Rigid Conductive Box, 90 x 64 x 16mm, 6mm HD in Base/FX in Lid $ 3.49
71247 Rigid Conductive Box, 108 x 83 x 13mm, 6mm HD in Base/FX in Lid $ 4.03
71250 Rigid Conductive Box, 230 x 128 x 20mm, 6mm HD in Base/FX in Lid $10.49
71252 Rigid Conductive Box, 230 x 128 x 30mm, 6mm HD in Base/FX in Lid $12.76
71254 Rigid Conductive Box, 230 x 128 x 40mm, 6mm HD in Base/FX in Lid $12.91
Click HERE for printable version | Sign Up HERE | Request a Sample HERE | See a list of Sales Reps HERE
Products & programs are available through your participating distributor | Submit an ESD Question HERE

About ESD Awareness

About Electrostatic Discharge

We have all seen static electricity in the form of lightning or perhaps felt the zap when reaching for a door knob. Similar types of electrical charges can have an effect on the electronic components you handle every day in your work. Unfortunately, their effect is much more hazardous and not as readily apparent.

Definition

Static electricity is an electrical charge at rest. Static electricity is most commonly created by friction and separation. Friction causes heat which excites the molecular particles of the material. When two materials are then separated, a transfer of electrons from one material to the other may take place.

As electrons transfer, the absence or surplus of electrons creates an electrical field known as static electricity. The simple separation of two materials, as when tape is pulled off a roll, can also create this same transfer of electrons between materials, generating static electrical fields.

The amount of static electricity generated depends upon the materials subjected to friction or separation, the amount of friction or separation and the relative humidity of the environment. Common plastic generally will create the greatest static charge. Low humidity conditions such as those created when air is heated during the winter will also promote the generation of significant static electrical charges.

Materials that easily transfer electrons (or charge) between atoms are called conductors and are said to have “free” electrons. Some examples of conductors are metals, carbon and the human body’s sweat layer. Materials that do not easily transfer electrons are called insulators. Some well known insulators are common plastics, glass and air. Both conductors and insulators may become “charged” with static electricity. When a conductor is charged, the free electrons give it the ability to discharge rapidly when it comes close to another conductor with a different potential.

Typical Electrostatic Voltages

Many of the common activities you perform daily may generate charges on your body that are potentially harmful to components.

Some of these activities include:

  • Walking across a carpet, 1,500 to 35,000 volts
  • Walking over untreated vinyl floor, 250 to 12,000 volts
  • Worker at a bench, 700 to 6,000 volts
  • Vinyl envelope used for work instructions, 600 to 7,000 volts
  • Picking up a common plastic bag from a bench, 1,200 to 20,000 volts

To continue reading About Electrostatic Discharge Awareness Click Here

Reducing Floor Maintenance Costs while Improving ESD Performance


by Rick Cardinale, Bird Electronic


Bird Electronic, founded in 1942 by J. Raymond Bird, soon became a leader in radio frequency instrumentation. Today, Bird also has moved into digital instrumentation test equipment.


With the development of digital instrumentation came the increased need for controls to prevent ESD events. Improving ESD protection has been an ongoing process since the late 1980s. In 1997, the company determined that an automated PCB production line would be installed and that the entire manufacturing area should be protected against ESD.


This decision led to an evaluation of ESD protective flooring. In 1998, 20,000 square feet of conductive floor tile were installed in the main production area. To help brighten the area, white tile was selected. The floor resistance measured less than 1.0 × 10^6 ohms.


High-Cost Maintenance


A bright, high-gloss appearance was part of the selection criterion for the floor. While the electrical properties were unchanging, by 1999, the floor was starting to dull. It was being maintained like a regular tile floor. No waxes or finishes were used; however, the tile manufacturer did recommend using buffing pads.


After consulting with the tile manufacturer and the installer, maintenance was increased to sweeping clean and damp mopping two times per week and buffing once per month. Monthly floor maintenance was $1,700 per month, a $20,400 annual expenditure.


In late 1999, the maintenance schedule was modified to add more buffing since this was the only way to keep the floor shiny. The floor now was swept and damp mopped weekly and buffed twice per month. The floor was clean and shiny, but the cost went up 41% to $2,400 per month, a $28,800 annual expenditure.

Click Here to continue reading Reducing Floor Maintenance Costs while Improving ESD Performance

Introducing New ESD White Lab Coats

72120

72125

  • Comfortable ESD dissipative lab coats are ideal for any production environment in which sensitive items (ESDS) are being handled
  • The coats offer ESD protection using the principle of the Faraday cage shielding ESDS from electrostatic charges on operator’s clothing
  • The buttons at the front have an overlap which avoids direct contact with parts

Click here to view New72120

Item Description Price
72120 Female, X – Small £49.29
72121 Female, Small £49.29
72122 Female, Medium £49.29
72123 Female, Large £49.29
72124 Female, X – Large £49.29
Item Description Price
72125 Male, Small £49.29
72126 Male, Medium £49.29
72127 Male, Large £49.29
72128 Male, X – Large £49.29
72129 Male, XX – Large £49.29
Sign up HERE | Request a sample HERE | See list of sales reps and distributors HERE
All items & programs are available through your participating distributor | Submit your questions HERE