19334 DESCO | Alldatasheet
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© 2022 DESCO INDUSTRIES INC Employee Owned 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 Full-Time Continuous Monitor Installation, Operation and Maintenance
Description
The Desco Full-Time Continuous Monitor is a single workstation continuous monitor. It continuously monitors the wiring of an AC outlet, path-to-ground integrity of one operator, and the ground plane of one ESD worksurface. Mounting tabs make it suitable to install in workbench or equipment settings. The embedded relay terminal activates when a pass condition is displayed on the monitor and can be connected to machines for access control or other devices. Connect the 19332 Light Tower accessory for increased alarm visibility. Connect the 19333 Power Relay accessory to control power to workbenches, hand tools, and other electronic devices dependent on the Full-Time Continuous Monitor's status. The Full-Time Continuous Monitor is designed with Wave Distortion Technology to provide stable continuous monitoring of the path-to-ground and presence of 1 megohm resistance of an operator’s wrist strap. Audio and visual alarms activate (in less than 500 milliseconds) when the operator unintentionally disconnects from the monitor or the wrist strap connection points are intermittent. The Full-Time Continuous Monitor also monitors for a worksurface path-to-ground of less than 10 megohms and the integrity of the electrical ground used to by the monitor. All Full-Time Continuous Monitors are calibrated to NIST standards and include a certificate. June 2022 Wave Distortion Technology is the Most Reliable Technology for the Continuous Monitoring of Single-Wire (Conductor) Wrist Straps “Wave Distortion” or vector impedance works by applying a continuous test voltage of 1.2 volts peak-to-peak at 1 to 2 microamperes (0.000002 amperes) to the wrist strap that is connected to the continuous or constant monitor. The test voltage creates a square wave that the monitor circuit compares to established patterns. By monitoring the “distortions”, or shape of the square wave, Wave Distortion Technology determines if the monitored circuit is complete - the operator is in the circuit and the total equivalent DC resistance is within specifications. Wave Distortion Technology produces a very fast alarm time and minimal false alarms. ANSI/ESD S20.20 section 7.3 states “Compliance verification records shall be established and maintained to provide evidence of conformity to the technical requirements.” Per ANSI/ESD S1.1 Annex A.3 Daily (wrist strap system) testing may be omitted if constant monitoring used.” Per ESD Handbook ESD TR 20.20 section 5.3.2.4.4 “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 knowledge of a continuous, reliable ground is needed, and then continuous monitoring should be considered or even required.” The Full-Time Continuous Monitor and its accessories are available as the following item numbers: Item Description
19330 Full-Time Continuous Monitor, with North
19331 Full-Time Continuous Monitor, with UK Power
19332 Light Tower
19333 Power Relay, North America
19334 Replacement Power Relay Interface Cord
19327 Replacement Power Cord, North America
19328 Replacement Power Cord, UK
98221 Wave Distortion Monitor Verification Tester
09842 Multi-Ground Hub
TECHNICAL BULLETIN TB-3092 Figure 1. Desco Full-Time Continuous Monitor
19330 Full-Time Continuous Monitor
1 Full-Time Continuous Monitor
1 Mat Monitor Cord (White)
1 Countersunk Washer
1 Flat Head Screw, 6-32 x 1/4"
2 Pan-Head Screws, #6 x 3/8"
1 Dual Lock Fastener Set, 2" Length
1 Power Cord with North American Plug
1 Certificate of Calibration
19331 Full-Time Continuous Monitor
1 Power Cord with UK Plug
1 Light Tower with Stereo Cord
4 Pan-Head Screws, #8 x 3/4"
Figure 2. Desco 19330 Full-Time Continuous Monitor Figure 3. Desco 19331 Full-Time Continuous Monitor Figure 4. Desco 19332 Light Tower packaging contents
create up to 12 ground points.
- +12VDC
- Green (open collector)
- Red (open collector) C. Park Snap: Allows the operator to disconnect (and park) a wrist strap when leaving the workstation, without creating a false alarm. Touch the park snap or park switch, and the monitor's audible alarm will disable for approximately 8 seconds. Use this time to disconnect the wrist cord from the wristband, and attach it to the park snap or remove the banana plug from the jack. Upon returning to the workstation and disconnecting the wrist cord from the park snap, the operator has approximately 8 seconds to reconnect the wrist cord to a worn wristband before activating the alarm. D. Monitored Operator Jack: Insert the single-wire wrist cord here to monitor the operator's connection to ground. E. Operator LEDs: Illuminates green when the operator is properly grounded. Illuminates solid red and audible alarm sounds when the operator is not properly grounded. F. Mat LEDs: Illuminates green when the worksurface is properly grounded. Illuminates red and audible alarm sounds when the worksurface is not properly grounded. G. Ground LEDs: Illuminates green when the AC outlet is properly wired and its path to equipment ground via the equipment ground conductor is intact. Illuminates red and audible alarm sounds when the AC outlet is not properly wired and its path to equipment ground via the equipment ground conductor is broken. H. Park Switch: Allows the operator to disconnect (and park) a wrist strap when leaving the workstation, without creating a false alarm. Touch the park snap or park switch, and the monitor's audible alarm will disable for approximately 8 seconds. Use this time to disconnect the wrist cord from the wristband, and attach it to the park snap or remove the banana plug from the jack. Upon returning to the workstation and disconnecting the wrist cord from the park snap, the operator has approximately 8 seconds to reconnect the wrist cord to a worn wristband before activating the alarm. The 8 second timer is indicated by the growing intensity of the park switch's blue LED. The blue LED will pulse when the operator jack is vacant to indicate standby mode. I. Power Inlet: Connect the included power cord here. J. Monitored Mat Terminal: Verifies that the worksurface's path-to-ground is less than 10 megohms. Connect the white mat monitor cord here.
Figure 5. Full-Time Continuous Monitor features and
- Fit the wristband snugly onto the wrist.
- Snap the wrist cord to the wristband.
- Plug the wrist cord into the operator jack. The green
operator is properly grounded.
- If this does not happen, examine the wrist cord for
- When leaving the workstation, first touch the
without sounding a false alarm.
- Upon returning to the workstation and disconnecting
sounding the monitor's alarm. Figure 8. Installing the 10 mm snap adapters to the Figure 9. Using the Full-Time Continuous Monitor when
magnitude and angle of the impedance. Figure 13. Mounting hole locations on the Full-Time