Question: Why do I only get a static shock when I touch metal?

Answer: Shocks are usually only felt if your body is charged to over about 4000V, and you touch something conductive (like metals or water, or other people).

If the wall or door is made of wood, concrete or some other material that has low or intermediate conductivity, any static charge on your body escapes slowly and usually does not cause a shock. If you touch metal, water, or another person when your body is highly charged, the charge is discharged quickly as the material is highly conductive. In this case you may feel a shock.

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.

Question:  Does the weather affect static electricity?

Answer: You’ll often find dry weather will affect static electricity.

Shocks are worst under certain weather conditions. Static shocks will increase during the winter when the air outside is cold and dry. They may disappear in warmer damper weather.

Static charge build-up is enhanced when the weather is dry so static problems are often noticed more in dry air of the winter. The air outside can be very dry when the weather is cold. Indoors, central heating or air conditioning can give very dry conditions which promote static electricity. Heating warms the air and reduces its humidity.

Static shocks are often noticed in cold dry weather, especially when in a centrally heated environment, and may disappear when the weather gets more humid. Static shocks may also be encouraged under air conditioning in hot weather.  Many people choose to use a humidifier to increase air moister which helps dissipate static charges.

When there are ESD concerns in environments such as semiconductor or electronics manufacturing, the ANSI20.20 requires that temperature and humidity readings are taken when measuring static.  Typically a static field meter or a surface resistance meter are use to measure static and many take these readings as well as measuring static.

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.

Question: Why do I experience static shocks in the office, when my colleagues do not?

Answer:  Short answer, there are lots of reasons. Lets review them:

There are many reasons why you might get static shocks in the office. Firstly, some people are just more sensitive to shocks than others. It like in life, people experience things differently, for example, some people can have music up louder than others. For most people, the threshold for feeling shocks is in the range  2,000-4,000V.

Secondly, you may be storing more static electricity than others. This depends on the size of your body and feet, and the thickness of your shoe soles! A bigger body, bigger feet, and thinner shoe soles, means more charge has to be stored to produce the same voltage. Try changing your shoes if you begin to experience static shocks regularly or consider a ESD chair mat, or an ESD chair.

Thirdly, you may be generating more charge than others. This may be due to the material of your shoe soles, or the way that you walk. If it happens when sitting, it may be due to the material of your clothes, and the amount of static they generate against your chair.  Insulators like plastics, polyester or nylon generate huge amounts of static.  Choose natural fibers or in extreme cases, try an ESD jackets which are used in manufacturing environments.

Question:  Are static shocks a health risk?

Answer: Static shocks can be a nuisance – but are not generally a health risk.

Fortunately there is little risk attached to such electrostatic discharges. In most cases they are just a common nuisance. The biggest risk is that a shock could cause you to have an accidental injury. For example, you might withdraw your arm suddenly and hit it against something.

Household static shocks, for example, are very high frequency and have a very short duration. According to LiveScience.com, it’s possible to generate up to 25,000 volts by dragging your feet across a carpet, though  the voltage of a typical carpet shock between a few hundred to a few thousand volts. People can typically feel static at 2000 volts. Either way, household static shocks are almost always harmless. Most of the shocks that electrocute people are at a much lower frequency, a much longer duration, and have more energy creating a much more significant driving force.

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.

 Question: Why do I get static shocks when I touch the door knob?

Answer: Static charges build up on shoes when you walk.

Most modern shoes have highly insulating rubber or plastic soles. As you walk, static charges can build up on the soles of the shoes. This is especially true if the floor is also insulating. Some older nylon carpets are particularly good at generating static electricity.  The charge on the shoes soles induces static electrical charge on your body, and when you touch something conductive, such as metal, the static will discharge and cause a the shock. If you are indoors, the point can be proved by walking around for a while with no shoes on – you will probably not experience shock.

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:  What is “ESD”?

A: ESD is short Electrostatic Discharge.

Electrostatic Discharge, or ESD, is a single-event, rapid transfer of electrostatic charge between two objects, usually resulting when two objects at different potentials come into direct contact with each other.  ESD can also occur when a high electrostatic field develops between two objects in close proximity.  ESD is one of the major causes of device failures in the semiconductor industry.

Electrostatic charge build-up occurs as a result of an imbalance of electrons on the surface of a material.  Such a charge build-up develops an electric field that has measurable effects on other objects at a distance.  The process of electron transfer as a result of two objects coming into contact with each other and then separating is known as ‘triboelectric charging’.

This charging process results in one object gaining electrons on its surface, and therefore becoming negatively charged, and another object losing electrons from its surface, and therefore becoming positively charged. A person can get triboelectrically charged in a number of ways, even by just walking across a room.

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:  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.