Work station monitor

Claim 3

The device of Claim 1 further comprising first indicator means responsive to said first and second monitoring means for indicating acceptable ground path resistance of both the wrist strap and the dissipative surface.

Claim 4

The device of Claim 2 wherein said first monitoring means includes means for disabling said timing means when an unacceptably high ground path resistance through the wrist strap and tether exists, said disabling means thereby causing said first monitoring means to latch to a constant ncn-pulsed output until the ground path resistance through the wrist strap and tether returns to an acceptable value.

Claim 5

The device of Claim 2 or 3 further comprising: second indicator means responsive to said first monitoring means for indicating an unacceptably high ground path resistance through the wrist strap and tether; third indicator means responsive to said first monitoring means for indicating an unacceptably low ground path resistance through the wrist strap and tether; and fourth indicator means responsive to said second monitoring means for indicating an unacceptably high ground path resistance through the dissipative surface.

Claim 6

The device of Claim 4 wherein: said first monitoring means further includes first and second voltage comparison means for establishing maximum and minimum strap resistance thresholds, respectively, for the grounding path through the wrist strap and tether; and said second monitoring means further includes third voltage comparison means for establishing a maximum surface resistance threshold for the grounding path through the dissipative surface.

Claim 7

The device of Claim 5 wherein: said first voltage comparison means outputs a low voltage level when the resistance through the wrist strap and tether is below said maximum strap resistance threshold, and outputs a high voltage level when the resistance through the wrist strap and tether is above said maximum strap resistance threshold; said third voltage comparison means outputs a low voltage level when the resistance through the dissipative surface is below said maximum surface resistance threshold, and outputs a high voltage level when the resistance through the dissipative surface is above said maximum surface resistance threshold; and said outputs of said first and third voltage comparison means are connected as inputs to a NOR gate, the output of said NOR gate being connected to said first indicator means.

Claim 8

The device of Claim 6 wherein: said first indicator means comprises a green LED; said second indicator means comprises a first red LED and an audible alarm; said third indicator means comprises a yellow LED; and said fourth indicator means comprises a second red LED.

Claim 9

A dual workstation monitor which alerts its user to the existence of unacceptable resistances in the ground paths of both an electrically dissipative surface and a conductive wrist strap having a grounding tether, comprising: a housing; a first jack located in said housing for receiving the grounding tether; a first wire for attachment to the electrically dissipative surface; a second jack located in said housing for receiving said first wire; a second wire for attachment to ground; a third jack located in said housing for receiving said second wire; a fourth jack located in said housing for connection to an external DC power supply; strap monitor means for continually monitoring the resistance of the ground path of the conductive wrist strap and grounding tether, said strap monitor means being connected to said first, third and fourth jacks, and including timing means for pulsing the output of said strap monitor means to said first jack; and surface monitor means for continually monitoring the resistance of the ground path of the dissipative surface, said surface monitor means being connected to said second, third and fourth jacks.

Claim 10

A dual workstation monitor which alerts its user to the existence of unacceptable resistances in the ground paths of both an electrically dissipative surface and a conductive wrist strap having a grounding tether, comprising: a housing; a first jack located in said housing for receiving the grounding tether; a first wire for attachment to the electrically dissipative surface; a second jack located in said housing for receiving said first wire; a second wire for attachment to ground; a third jack located in said housing for receiving said second wire; a fourth jack located in said housing for connection to an external DC power supply; strap monitor means for continually monitoring the resistance of the ground path of the conductive wrist strap and grounding tether, said strap monitor means being connected to said first, third and fourth jacks, and including timing means for pulsing the output of said strap monitor means to said first jack; and surface monitor means for continually monitoring the resistance of the ground path of the dissipative surface, said surface monitor means being connected to said second, third and fourth jacks.

Claim 11

The dual workstation monitor of Claim 8 further comprising: first indicator means responsive to said strap and surface monitor means for indicating contemporaneous acceptable ground path resistances of both the wrist strap and the dissipative surface; second indicator means responsive to said strap monitor means for indicating an unacceptably high ground path resistance through the wrist strap and tether; third indicator means responsive to said strap monitor means for indicating an unacceptably low ground path resistance through the wrist strap and tether; and fourth indicator means responsive to said surface monitor means for indicating an unacceptably high ground path resistance through the dissipative surface.

Claim 12

The dual workstation monitor of Claim 9 wherein: said strap monitor means further includes first and second voltage comparison means for establishing maximum and minimum strap resistance thresholds, respectively, for the grounding path through the wrist strap and tether; and said surface monitor means further includes third voltage comparison means for establishing a maximum surface resistance threshold for the grounding path through the dissipative surface.

Claim 13

The dual workstation monitor of Claim 10 further wherein: said first voltage comparison means includes a first operational amplifier which outputs a low voltage level when the resistance through the wrist strap and tether is below said maximum strap resistance threshold, and outputs a high voltage level when the resistance through the wrist strap and tether is above said maximum strap resistance threshold; said third voltage comparison means includes a second operational amplifier which outputs a low voltage level when the resistance through the dissipative surface is below said maximum surface resistance threshold, and outputs a high voltage level when the resistance through the dissipative surface is above said maximum surface resistance threshold; and said outputs of said first and second operational amplifiers are connected as inputs to a NOR gate, the output of said NOR gate being connected to said first indicator means.