19334

## DESCO **TECHNICAL BULLETIN TB-3092 Full-Time Continuous Monitor Installation, Operation and Maintenance** 

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Made in the<br>United States of America<br>**----- End of picture text -----**<br>


**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. 

_Figure 1. Desco Full-Time Continuous Monitor_ 

## **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. 

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**<br>**Description**<br>19330<br>Full-Time Continuous Monitor, with North<br>America Power Cord<br>19331<br>Full-Time Continuous Monitor, with UK Power<br>Cord<br>19332<br>Light Tower<br>19333<br>Power Relay, North America<br>19334<br>Replacement Power Relay Interface Cord<br>19327<br>Replacement Power Cord, North America<br>19328<br>Replacement Power Cord, UK<br>98221<br>Wave Distortion Monitor Verification Tester<br>_LSS|
|---|
|09842<br>Multi-Ground Hub|



**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 

© 2022 DESCO INDUSTRIES INC Employee Owned 

**TB-3092** Page 1 of 7 June 2022 

## **Packaging** 

## **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 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 

_Figure 2. Desco 19330 Full-Time Continuous Monitor packaging contents_ 

- 1 10mm Interchangeable Park Snap 

- 1 10mm Operator Jack Adapter 

- 1 Power Cord with UK Plug 

- 1 Certificate of Calibration 

## **19332 Light Tower** 

1 Light Tower with Stereo Cord 4 Pan-Head Screws, #8 x 3/4" 

_Figure 3. Desco 19331 Full-Time Continuous Monitor packaging contents_ 

_Figure 4. Desco 19332 Light Tower packaging contents_ 

**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 

© 2022 DESCO INDUSTRIES INC Employee Owned 

**TB-3092** Page 2 of 7 

## **Features and Components** 

**A. Monitored Ground Terminal:** Provides a verified ground point. Bond to the 09842 Multi-Ground Hub to create up to 12 ground points. 

**B. Light Tower Jack:** Connects to the 19332 Light Tower accessory. ——— I 

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_Figure 5. Full-Time Continuous Monitor features and components_ 

- +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. 

**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 

© 2022 DESCO INDUSTRIES INC Employee Owned 

**TB-3092** Page 3 of 7 

**K. Set Switch:** Toggles the monitor's settings for the audible alarm and mat monitor circuit. 

1. Remove the Full-Time Continuous Monitor from the carton, and inspect for damage. 

2. Determine the mounting location of the Full-Time Continuous Monitor. Its LEDs should be visible to the operator. Secure the Full-Time Continuous Monitor to a surface using its mounting tabs and the included pan head screws or dual lock fasteners. 

|**Function**||||**Procedure**||2. Determine the mounting location of the Full-Time<br>Continuous Monitor. Its LEDs should be visible|2. Determine the mounting location of the Full-Time<br>Continuous Monitor. Its LEDs should be visible|2. Determine the mounting location of the Full-Time<br>Continuous Monitor. Its LEDs should be visible|2. Determine the mounting location of the Full-Time<br>Continuous Monitor. Its LEDs should be visible|2. Determine the mounting location of the Full-Time<br>Continuous Monitor. Its LEDs should be visible|2. Determine the mounting location of the Full-Time<br>Continuous Monitor. Its LEDs should be visible|
|---|---|---|---|---|---|---|---|---|---|---|---|
|Audible Alarm||Audible Alarm||1. Push and release the switch to||to the operator. Secure the Full-Time Continuous|||||to the operator. Secure the Full-Time Continuous|
|Volume||||toggle the buzzer's volume.||Monitor to a surface using its mounting tabs and the||||||
|||||2. The volume will toggle from low,||included pan head screws or dual lock fasteners.|||included pan head screws or dual lock fasteners.|||
|Enable / Disable||||medium, and high settings.<br>1. Push and hold the switch until||3. Secure the ring termination of the white mat monitor<br>cord to the monitored monitor terminal on the back||||||
|Mat Monitor||||all LEDs illmuniate orange.||of the Full-Time Continuous Monitor.|||||of the Full-Time Continuous Monitor.|
|Circuit||||2. Release the switch.<br>3. An illuminated MAT LED<br>indicates that the mat||4. Connect the mat monitor cord from the back of<br>the Full-Time Continuous Monitor to a grounded<br>worksurface mat. Use the included countersunk||||||
|||||monitor circuit is enabled. A||washer and flat head screw to secure the cord to||||||
|||||non-illuminated MAT LED||the grounded mat.||||||
|||||indicates that the mat monitor||||||||
|||||circuit is disabled.||5. Connect the power cord to the power inlet located||||||
|||||||on the back of the Full-Time Continuous Monitor.||||||
|**L. Relay Terminal:**Integrates with electronic locks,<br>lights, buzzers, etc. See the "Relay Terminal" section for|||||lights, buzzers, etc. See the "Relay Terminal" section for|Connect the opposite end to an appropriate AC<br>outlet.||||||
|more information.||||||||||||
|**M. Auxilary Jack:**Connects to the 19333 Power Relay<br>accessory. SeeTB-3093for more information.||||||**Relay Terminal**<br>The Full-Time Continuous Monitor features a relay<br>terminal that can be integrated with electronic locks,||||||
|**Installation**|**Installation**|**Installation**||||lights, buzzers, etc. The relay will activate when a failure<br>is reported by the Full-Time Continuous Monitor.||||||
|**Full-Time Continuous Monitor**|**Full-Time Continuous Monitor**|||||||||||
|||||||Contact Form<br>2 Form C|||2 Form C|||
|||||||Maximum SwitchingPower<br>60 W, 125 VAC||||||
|||||||Maximum SwitchingVoltage<br>220 VDC, 250 VAC|||||220 VDC, 250 VAC|
|||||||Maximum SwitchingCurrent<br>2 A||||||
|||||||Maximum CarryingCurrent<br>2 A||||||
|||||||||||||
|||Power Cord||||||||||
||Full-Time|||||||||||
|Continuous Monitor||||||||||||
|||||Mat Monitor Cord<br>|||**NC**<br>**C**<br>_Figure 7. Relay terminal contacts_|||||**NO**|
|Grounded||||||||||||
|Worksurface Mat|Worksurface Mat|||||||||||
|c—<br>5||||Countersunk Washer<br>Flat Head Screw<br>©<br>8||||||||



3. Secure the ring termination of the white mat monitor cord to the monitored monitor terminal on the back of the Full-Time Continuous Monitor. 

**L. Relay Terminal:** Integrates with electronic locks, lights, buzzers, etc. See the "Relay Terminal" section for more information. 

**M. Auxilary Jack:** Connects to the 19333 Power Relay accessory. See TB-3093 for more information. 

The Full-Time Continuous Monitor features a relay terminal that can be integrated with electronic locks, lights, buzzers, etc. The relay will activate when a failure is reported by the Full-Time Continuous Monitor. 

## **Installation** 

## **Full-Time Continuous Monitor** 

_Figure 6. Installing the Full-Time Continuous Monitor_ 

**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 

© 2022 DESCO INDUSTRIES INC Employee Owned 

**TB-3092** Page 4 of 7 

## **10 mm Snap Adapters** 

The 19331 Full-Time Continuous Monitor includes an interchangeable 10 mm park snap and 10 mm banana jack adapter for operators who use wrist cords with 10 mm terminations. Use the park snap's knurled rim to unscrew the 4 mm park snap from the monitor and install the 10 mm park snap to the monitor. Plug the 10 mm operator jack adapter into the monitor's operator jack. 

_Figure 8. Installing the 10 mm snap adapters to the 19331 Full-Time Continuous Monitor_ 

## **Operation** 

1. Fit the wristband snugly onto the wrist. 

_Figure 9. Using the Full-Time Continuous Monitor when mounted underneath a workbench tabletop_ 

2. Snap the wrist cord to the wristband. 

3. Plug the wrist cord into the operator jack. The green operator LED will illuminate. This indicates that the operator is properly grounded. 

4. If this does not happen, examine the wrist cord for continuity or damage and the wristband to ensure that it fits securely. If you have dry skin, apply an approved dissipative hand lotion such as Menda Reztore® ESD Hand Lotion. 

5. When leaving the workstation, first touch the monitor's park switch or park snap. 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 without sounding a false alarm. 

6. Upon returning to the workstation and disconnecting the wrist cord from the park snap, the monitor will provide approximately 8 seconds for the operator to reconnect the wrist cord to a worn wristband before sounding the monitor's alarm. 

**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 

© 2022 DESCO INDUSTRIES INC Employee Owned 

**TB-3092** Page 5 of 7 

## **Calibration** 

Frequency of recalibration should be based on the critical nature of those ESD sensitive items handled and the risk of failure for the ESD protective equipment and materials. In general, Desco recommends that calibration be performed annually. 

Use the Desco 98221 Wave Distortion Monitor Verification Tester to perform periodic verification (once every 6-12 months) of the Full-Time Continuous Monitor. The verification tester can be used to check the test limits of the Full-Time Continuous Monitor without removing it from the workstation. 

See TB-3074 for more information. 

_Figure 10. Using the Full-Time Continuous Monitor when mounted on a workbench upright_ 

_Figure 12. Desco 98221 Wave Distortion Monitor Verification Tester_ 

_Figure 11. Using the Full-Time Continuous Monitor at a machine station_ 

**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 

© 2022 DESCO INDUSTRIES INC Employee Owned 

**TB-3092** Page 6 of 7 

## **Specifications** 

## **Full-Time Continuous Monitor** 

|Input Voltage and<br>Frequency|Power Input:<br>100-240 VAC, 50/60 Hz|
|---|---|
||Power Cord Length:<br>6 ft. (1.8 m)|
|Operating Temperature <br>Environmental|50 to 95° F (10 to 35° C)<br>Indoor use only at altitudes|
|Requirements|less than 6500 ft. (2 km)|
||Maximum relative humidity|
||of 80% up to 85° F (30° C)|
||decreasing linearly to 50% @<br>85° F (30° C)|
|Dimensions|2.85" L x 5.13" W x 1.00" H|
||(72 mm x 130 mm x 25 mm)|
|||
|Weight|0.35 lbs. (0.16 kg)|
|||
|Operator Test Range*|500 kilohms to 10 megohms|
||impedance|
|||
|Worksurface Test<br>Limit**|10 megohms (±20%)|
|Operator Test Voltage|1.2 V peak-to-peak @ 1.2 µA,|
||open circuit|
|Worksurface Test|5 to 7.5 V, open circuit|
|Voltage||
|||
|Alarm Response Time|<500 ms|
|||
|Country of Origin|United States of America|



*This cannot be verified with standard DC test equipment. The continuous monitor is an impedance sensing device, and the limits are determined by the magnitude and angle of the impedance. 

**The worksurface mat must have a conductive layer such as Dual Layer Rubber or Dissipative 3-Layer Vinyl with conductive buried layers. Desco workstation monitors are not recommended for use with homogeneous matting. 

_Figure 13. Mounting hole locations on the Full-Time Continuous Monitor (all dimensions are in inches)_ 

## **Light Tower** 

|Input Voltage|12-24 VDC|
|---|---|
|Dimensions|2.8" L x 2.8" L x 8.9" H|
||(70 mm x 70 mm x 225 mm)|
|Weight|0.5 lbs. (0.23 kg)|
|Cable Length|6 ft. (1.8 m)|
|Country of Origin|China|



## **Limited Warranty, Warranty Exclusions, Limit of Liability and RMA Request Instructions** 

See the Desco Warranty - Desco.com/Limited-Warranty.aspx 

ANSI/ESD S20.20 requires the use of a surface resistance meter for periodic verification of a worksurface's resistance-to-ground (Rtg). Constant monitors may not be used as a substitute for this requirement. 

**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 

© 2022 DESCO INDUSTRIES INC Employee Owned 

**TB-3092** Page 7 of 7