TECHNICAL BULLETIN TB-3050 Jewel Workstation Continuous Mini Monitor Operation, Installation and Maintenance Made in the United States of America A broken wrist strap may expose products to ESD over an entire shift if it is checked only at shift change with wrist strap checker. (ESD TR 12-01 Section 4.2 Selection Considerations) The Jewel Workstation Continuous Monitor eliminates the need for periodic wrist strap tests and logging. 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 products have been manufactured. The costs of dealing with the resulting catastrophic or latent defects can be considerable. Jewel Workstation Continuous Mini Monitors eliminate the need for operaters to test wrist straps and log the results by their function, these Figure 1. Desco 19218 Jewel Workstation Continuous monitors satisfy the ISO 9000 and ANSI/ESD S20.20 Mini Monitor test logging. ANSI/ESD S20.20 Section 6.2.2.2 Personnel Grounding Guidance states A log should be maintained which verifies that personnel have tested Description their personal grounding devices. Per ANSI/ESD-S1.1 The Jewel Workstation Continuous Mini Monitor Annex A Section 6.1.3 Daily (wrist strap system) testing independently monitors the operator and the may be omitted if constant monitoring is used. Per worksurface. The instant an operators wrist strap or ANSI/ESD-S1.1 Annex A Frequency of Functional cord fails, the monitor will issue audible and visual Testing, The wrist strap system should be tested daily alarms alerting the user of the problem. In the same to ensure proper electrical value. Daily testing may be manner, the unit also confirms that a path to ground omitted if constant monitoring is used. of less than 500 megohms exists from the ESD worksurface. Park Snap The Jewel Workstation Continuous Monitor is a Single All Desco single-wire monitors with wave distortion Conductor Impedance Sensing Continuous Monitor technology include the Park Snap feature. Use the which per ESD Handbook TR20.20 section 5.3.9.2.1 a Park Snap to store the operators wrist cord and enable small AC voltage is used in a detection circuit designed standby mode while the operator is away from the to eliminate false alarms and adjustment. They use the workstation. Before disconnecting the coil cord from the phase difference between current and voltage to detect wristband, the operator touches the Park Snap to disable changes in impedance of the grounding cord, wristband the audio alarm for 6 seconds. Within the 6 second and person. No adjustments are required. period, the operator can disconnect their wrist cord from their wristband and attach it to the Park Snap before the Per ESD Handbook ESD TR20.20 section 5.3.2.4.4, audible alarm sounds. Typical test programs recommend that wrist straps that are used daily should be tested daily. However, if the products that are being produced are of such value that Wave Distortion Detection Technology knowledge of a continuous, reliable ground is needed, Provides True 100% Continuous Monitoring and then continuous monioring should be considered or Wave distortion impedance circuitry monitors current / even required. voltage phase shifts and provides true 100% continuous monitoring. Electrical current will lead voltage at various Advantages Of Continuous Monitoring points due to the combinations of resistance and Over Periodic Testing capacitive reactance. By monitoring these distortions or phase shifts, the Jewel Workstation Continuous Mini When considering constant or continuous monitors, Monitor will reliably determine if the circuit is complete. the equipment cost including the wrist strap, maintenance and training cost, labor time for performing wrist strap tests, and the potential failures due to non- functional wrist straps should be considered. DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 (909) 627-8178 DESCO EAST - One Colgate Way, Canton, MA 02021-1407 (781) 821-8370 Website: Desco.com 2014 DESCO INDUSTRIES, INC. TB-3050 Page 1 of 4 October 2014 Employee OwnedWave distortion technology can be referred to as vector Worksurface Channel impedance monitoring. This description is valid as the The Jewel Workstation Continuous Mini Monitor wave distortion technology measures the impedance monitoring circuitry is sufficiently sensitive to detect at the monitored banana jack and looks for changes in extremely low current, allowing it to be used with mats either the capacitance or resistance of the circuit which 8 having a resistance of up to 5 x 10 ohms RTG. When includes the wrist strap and its wearer. It uses filtering the Monitor is connected to an ESD Mat worksurface, and time domain sampling to filter out false signals the amount of current that flows is a function of the caused by voltage offsets, 60 Hz fields and other electro- total resistance between the monitor and through the magnetic and electrostatic interference. worksurface to ground. When the resistance of the worksurface is below a pre-set threshold, the monitor In normal factory environments, and with persons whose will indicate good. Conversely, if the resistance level is capacitance with respect to ground is within design limits high when compared to the monitors reference, the unit (5 feet tall 90 pound person to 6 foot 5 inch 250 pound will alarm. This is an integrating resistance measuring person), the Jewel Workstation Continuous Mini Monitor circuit, therefore it is relatively insensitive to externally cannot be fooled. It will provide a reliable alarm only induced electromagnetic fields. The resistance threshold when the wrist strap or work surface becomes is factory set to 500 megohms. (It can be special dysfunctional or unsafe according to accepted industry ordered to other limits. Limits can be varied and set to 1 standards. The Jewel Workstation Continuous Mini gigohm maximum.) Monitor is drift-free and designed to be insensitive to the effects of squeezing or stretching the coil cord. Packaging Advantages Of Wave Distortion And Single- 1 Jewel Workstation Continuous Mini Monitor 2 Push and Clinch Snaps Wire Technology 1 Power Adapter, 24VAC, N. America The Jewel Workstation Continuous Mini Monitor 1 Certificate of Calibration allows the use of any standard, single-wire wrist strap and coil cord. The monitor / wrist strap / cord system Installation life-cycle costs are by far lower than alternative systems which require expensive and less durable dual-wire Confirm that the surface resistance (RTG) of the mat is 8 cords and special wrist straps. The Jewel Workstation 5 x 10 ohms or less and has a conductive layer. We Continuous Mini Monitor is an economical way to recommend the Desco 19787 or 19784 Meter. Remove monitor both the operators wrist strap and workstation the monitor from its packaging and inspect for any surface. See Maintenance and Calibration (page 4) to shipping damage. minimize life-cycle costs. The Continuous Mini Monitor is normally installed toward The dictionary defines constant as uniform and the front edge of a workstation where the LEDs are unchanging, and continuous as uninterrupted. easily visible. The unit is designed to be snapped on the Nonetheless, some dual-wire resistance monitors utilize worksurface using the 10mm snap studs mounted at the a pulsed test current and do not provide continuous bottom of the monitor (see Figure 2). monitoring. For example, during each 2.2 second pulse cycle of a leading constant resistive monitor, electrical ESD MAT current is pulsed for only 0.2 seconds followed by an unmonitored interval of 2 seconds. This leaves the user / wrist strap unmonitored for over 90% of each cycle. Damaging static charges can easily occur in the portion Push and Clinch Snaps of the time in between the pulses. The off period of 2 seconds equals 2 billion nanoseconds, and it takes only about 25 volts applied for 100 nanoseconds to blow most memories or microprocessors.* By using the reliable wave distortion impedance technology to determine if the circuit is complete, there 1-5/16 are no false alarms. There is no need to adjust or tune the monitor to a specific user or installation. The miniscule amount of electrical current (less than 1 volt coil cord signal) required to generate the waveform has Figure 2. Installation of push and clinch snaps to never caused reported skin irritation and is extremely worksurface safe for use in voltage sensitive applications such as disk drive manufacturing. DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 (909) 627-8178 DESCO EAST - One Colgate Way, Canton, MA 02021-1407 (781) 821-8370 Website: Desco.com 2014 DESCO INDUSTRIES, INC. TB-3050 Page 2 of 4 Employee Owned