TECHNICAL BULLETIN TB-3028 Multi-Mount Continuous Monitor Made in America Operation, Installation, and Maintenance The Multi-Mount Continuous Monitor is a real time instrument that ensures that critical ESD generators in a sensitive area are effectively grounded. The instant an operators wrist strap or cord fails, the monitor will issue audible and visual (LEDs) alarms alerting the user and supervisor of the problem. The Parking Snap features provides a means for the operator to disconnect wrist strap cord when normally leaving work area without audible alarm sounding. It also provides a means of wrist strap storage. ADVANTAGES OF CONTINUOUS MONITORING OVER PERIODIC TESTING Many customers are eliminating periodic testing and are utilizing continuous monitoring to better ensure that their products were manufactured in an ESD protected environment. Full time continuous monitoring is superior to periodic or pulsed testing, and can save a significant amount of money in testing costs and rejected product. Periodic testing detects failures after ESD susceptible Figure 1. Desco Multi-Mount Continuous Monitor products have been manufactured. The costs of dealing with the resulting catastrophic or latent defects can be Description considerable. Multi-Mount Continuous Monitors eliminate Leading companies use continuous monitors as a cost the need for users to test wrist straps and log the results effective component in satisfying the paragraph 6.1.3 by their function, these monitors satisfy the ISO 9000 Compliance Verification Plan requirements of ANSI/ and ANSI/ESD S20.20 test logging. ANSI/ESD S20.20 ESD S20.20. The Desco Multi-Mount Continuous Monitor Paragraph 6.2.2.2 Personnel Grounding Guidance states A continuously monitors the integrity of one operator. This log should be maintained which verifies that personnel have monitor will provide virtually instantaneous notification tested their personal grounding devices. Per ESD-S1.1 of static control equipment failures, eliminating the need Paragraph 6.1.3 Daily (wrist strap system) testing may be of periodic testing and costly record keeping. This unit omitted if constant monitoring is used. is highly cost effective as it is designed to monitor any conventional single wire wrist strap and ground cord WAVE DISTORTION DETECTION TECHNOLOGY system. Its small package and mounting tabs with holes PROVIDES TRUE 100% CONTINUOUS MONITORING make it highly suitable to install on most any equipment From all the technical alternatives available, Desco or work bench surface. In addition, optional mounting is has chosen wave distortion technology for many of its available using the provided adhesive-backed Velcro Continuous Monitor product offerings. Wave distortion strips. Using either mounting method makes the circuitry monitors current/voltage phase shifts and provides Multi-Mount Monitor suitable for most any machinery or true 100% continuous monitoring. Electrical current will workbench even in hard to reach locations. lead voltage at various points due to the combinations of resistance and capacitive reactance. By monitoring these The Desco Multi-Mount Continuous Monitor is available in distortions or phase shifts, the wave distortion Multi-Mount two models: Continuous Monitor will reliably determine if the circuit is complete. Wave distortion technology can be referred to vector Model Voltage AC Calibration impedance monitoring. This description is valid as the 19226 120 NIST wave distortion technology measures the impedance at the monitored banana jack and looks for changes in either the 19227 220 NIST capacitance or resistance of the circuit which includes the wrist strap and its wearer. It uses filtering and time domain sampling to filter out false signals caused by voltage offsets, 60 Hz fields and other electro-magnetic and electrostatic interference. DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 (909) 627-8178 Fax (909) 627-7449 DESCO EAST - One Colgate Way, Canton, MA 02021-1407 (781) 821-8370 Fax (781) 575-0172 Web Site: Desco.com 2011 DESCO INDUSTRIES INC. TB-3028 April 2011 Page 1 of 4 Employee OwnedIn normal factory environments, and with persons whose capacitance with respect to ground is within design limits H (5 feet tall 90 pound person to 6 foot 5 inch 250 pound G A person), the Multi-Mount Continuous Monitor cannot be fooled. It will provide a reliable alarm only when the F wrist strap becomes dysfunctional or unsafe according to accepted industry standards. The Multi-Mount Continuous B Monitor is drift-free and designed to be insensitive to the effects of squeezing or stretching the coil cord. ADVANTAGES OF WAVE DISTORTION AND SINGLE-WIRE TECHNOLOGY The Desco Multi-Mount Continuous Monitor allows the use C D E of any standard, single-wire wrist strap and coil cord. The monitor/wrist strap/cord system life-cycle costs are by far Figure 2. Multi-Mount Continuous Monitor features and lower than alternative systems which require expensive & components fragile dual-wire cords and special wrist straps. Dual-wire cords are expensive and are the weak link of the system, Features and Components (See Figure 2) the most likely component to need replacement. Over a five year period, this can make the dual-wire system three A. Status LEDs: When the green LED is lit, the operator is to five times as expensive as a system utilizing single-wire properly grounded. When the red LED is lit, the operator is wrist straps and cords. See Maintenance and Calibration not properly grounded. (page 4) to minimize life-cycle costs. B. Monitored Operator Jack: Where the operator inserts The dictionary defines constant as uniform and unchanging, the wrist cord banana plug. and continuous as uninterrupted. None theless, some C. Worksurface Ground LEDs: When the green LED is dual-wire resistance monitors utilize a pulsed test current lit, the work surface mat is properly ground. When the red and do not really provide continuous monitoring. For LED is lit, the work surface mat is not properly grounded. example, during each 2.2 second pulse cycle of a leading constant resistive monitor, electrical current is pulsed for D. Operator Ground LEDs: When the green LED is lit, the only 0.2 seconds followed by an unmonitored interval of operator is properly grounded. When the red LED is lit, the 2 seconds. This leaves the user/wrist strap unmonitored operator is not properly grounded. for over 90% of each cycle. Damaging static charges can easily occur in the portion of the time in between the pulses. E. 4mm Parking Snap: When touched by the operator, this The off period of 2 seconds equals 2 billion nanoseconds, snap will deactivate the alarm for six seconds. This allows and it takes only about 25 volts applied for 100 time for the operator to disconnect the coil cord from the nanoseconds to blow most memories or microprocessors.* wrist band and park it on this snap. While parked, the coil The dual-wire system does not reliably meet all industry cord disables the alarm, allowing the operator to leave the specifications, as the cords do not meet the EOS/ESD workstation. The OPERATOR GROUND LED will remain S-1.0 paragraph 4.1.6, 1 to 5 pound breakaway force off while the cord is parked. Upon returning and removing requirement for operator safety. the coil cord from the parking snap, the operator has six seconds to hook up to the wrist band before the alarm By using the reliable wave distortion technology to sounds. determine if the circuit is complete, there are no false alarms. There is no need to adjust or tune the monitor to F. 24 VAC Power Jack: Connect the power adapter here. a specific user or installation. The miniscule amount of electrical current (less than 1 volt coil cord signal) required G. Mat Connection: Monitors worksurface mat. NOTE: To to generate the waveform has never caused reported skin disable worksurface monitoring, shunt this terminal to the irritation and is extremely safe for use in voltage sensitive neighboring GND terminal with a bus wire. applications such as disk drive manufacturing. H. Mat Ground: Grounds worksurface mat. Installation Remove the monitor from its packaging and inspect for any shipping damage. Confirm that the work surface is 1 x 10E7 ohms or less and has a conductive layer such as Dual Layer Rubber, Dissipative 3-Layer Vinyl, or Micastat Dissipative Laminate with conductive buried layers. *1981 article by Donald E. Frank - Electrical Overstress / Electronic Discharge Symposium Proceedings DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 (909) 627-8178 Fax (909) 627-7449 DESCO EAST - One Colgate Way, Canton, MA 02021-1407 (781) 821-8370 Fax (781) 575-0172 Web Site: Desco.com 2011 DESCO INDUSTRIES INC. TB-3028 Page 2 of 4 Employee Owned