Because selecting an appropriate technology to affect useful static control is complex, we offer help through our toll free number. Our application engineers can help you select the best technology for your need. However, some of the considerations we take into account are the application environment, placement and size restrictions, an estimate of the charge generation rate, the required neutralization rate, and the tolerable residual voltage after treatment. For example, suppose your application involves removing a static charge from a plastic part in a volatile atmosphere. In this case, the overriding consideration is the volatile atmosphere and we would recommend the alpha technology because it utilizes no electrical power supply, which could trigger a fire or explosion. Another application that would benefit from alpha technology is removing static generated during the manufacture of read and write heads for use in computer hard drives. These devices are sensitive to very low voltages, and alpha technology always produces an equal number of positive and negative ions, which can, with high reliability, bring the residual voltage to zero. In the absence of a volatile atmosphere, an example of where we might recommend electrical technology would be one where there were large sheets of material, such as 4' by 10' plastic, coming off a press or roller and they are highly charged with static electricity.
Alpha ionizers use a radioactive element that emits Helium ions from its nucleus. The emitted Helium ion has sufficient energy to travel about 3 centimeters in air. As it travels it strips electrons from surrounding air molecules. Each gas molecule that loses an electron becomes a positive ion. The free electron quickly attaches to another gas molecule and it becomes a negative ion. In this way, each alpha particle that is emitted always creates one positive and one negative ion. Hence, alpha ionizers produce an intrinsically balanced output.
Corona (AC) ionizers work by applying an alternating high voltage to the tip of a sharp point producing an electrostatic field in the vicinity of the point. This electrostatic field is of sufficient strength to cause electrons to be stripped from the air molecules within the field. During the positive half of the AC cycle, the free electrons quickly attach to a nearby air molecule and are attracted toward the point while the resulting positive air molecule is repelled from the point. During the negative half the AC cycle, the effects are reversed. Positive ions are attracted to the point and negative ions are repelled.
Because each product is designed for a different application, it may have unique mounting, power, or environmental requirements. Our application engineers are trained to assist you select the best static eliminator for your application, and will discuss any special requirements with you. Every static eliminator is delivered with installation, care and operating instructions. If you have any questions or concerns, please call our toll free number.
Our alpha ionizer static eliminators contain a small amount of radioactive material and are considered sealed sources. Before NRD is granted a license to manufacture and distribute a static eliminator containing radioactive material, the design must pass a safety analysis and battery of tests mandated by state and federal agencies, and defined by ANSI/ISO standards. Our manufacturing processes and quality assurance procedures are reviewed and audited to assure compliance. Every alpha ionizer is leak tested before shipment. NRD has been manufacturing and distributing alpha ionizers for over 30 years, and during that time the only instances of contamination were when the integrity of an ionizer was compromised by physical abuse, such as drilling a hole through it or cutting it. If you have any questions or concerns, please call our toll free number.
Shockless static eliminators are constructed so that the emitter pins are capacitively coupled to the high voltage source. This limits the current at the emitters. Direct contact with the points will not result in an electric shock.
Hot static eliminators are constructed so that the emitter pins are directly coupled to the high voltage power supply.
NRD offers both types of ionizers.
Alpha ionizers should never be cleaned using any type of solvent or aqueous solution. If dust or dirt has settled in your device, it can be blown off using clean and dry compressed air. If using compressed air is not sufficient to clean the debris from the device, it should be returned to NRD for evaluation.
Before attempting to clean the device, always assure it is disconnected from the power supply. Using clean and dry compressed air, blow off the device. A stiff brush can be used to clean around the emitter pins. If required, Isopropyl alcohol can be used to remove accumulated paint or ink build-up. Wipe off the solvent with a clean dry cloth.
Shielded cable has a braided metal exterior cover and reduces the amount of electromagnetic interference (EMI) and radio frequency interference (RFI) emitted from the cable.
RD's Model 6000 Power Supply can accommodate 120 linear inches of bar per transformer and 25 feet of shielded cable.
NRD Alpha ionizers use a small amount of radioactive material that has a half-life of 138 days. After 12 months have elapsed, the activity of the device has reduced to 15% of it original activity and should be replaced to assure optimal static control of your process. In addition, the regulatory body that governs the manufacture and distribution of our devices requires that all our alpha products be inspected 13 months after manufacture. By returning the device to NRD, we can perform the required testing on our customer's behalf.
The amount of moisture present in the air can affect the conductivity of insulating materials and their ability to hold a static charge. The higher the moisture content in the air, the more conductive a material becomes. Conversely, the dryer the air is, the more insulative the material becomes allowing it to hold a greater charge. Although controlling humidity can be helpful, it is a very slow process and often does not afford sufficient reduction in charge to be a complete solution to the problems caused by static charging.