Shield-Check & it's ESD Discharge Simulator, have been designed as a quick check indicator to quantify the maximum voltage seen inside a metallized shielding bag. ESD Discharge Simulator (1000D) delivers, a (HBM) Human body model charge of 1000 volts. Shield-Check (SC-0-300) records the peak voltage seen inside the bag, via a row of LED's sensing 10-20-30-40-50-100-200- 300 volts. The maximum voltage sensed will remain visible until the operator presses the reset switch.

		Our portable mains powdered ESD Discharge simulator and near credit card size Shield-Check sensor, can be used for a quick evaluation of new and used shielding bags. Complete with Stainless steel Discharge probe, Reference plate, and test leads. SC-0-300 POWER: 3 x 3 volt lithium coin cell batteries CR2032 1000D POWER: mains 120/240Ac SC-0-300 SIZE: 106mm x 60mm x 21mm 1000D SIZE: 150mm x 115mm x 57mm

Questions and Answers about Shield-Check
Why use a (HBM) Human Body Model of 1000 volts?
Other Voltages may be used at the operators discretion, however users should be sensitive to the voltage breakdown limitations of the material under test as well as the various components used in the Shield- Check sensor.

Why is the sensor unit near credit card size?
This allows the user to measure the performance of almost any size of metallized shielding bag.

Why should the user not touch the probe, bag under test or reference plate, whilst delivering 1000v (HBM) from the discharge simulator?
The sensor detects the differential voltage between top and bottom sensing discs through the shielding bag. If the users touches the probe, bag, or reference plate, the 1000v (HBM) will reference to the user rather than reference plate.

What if no voltage LED's light after the 1000v discharge has been made?
This is due to the effective shielding of the bag under test I.E. less than 10 volts has been sensed.

If the 10 volt LED lights what voltage has been sensed?
10 volts or greater than 10 volts but less than 20 volts. The same principal applies for 20 volts 30 volts etc.,

Will a good quality large shielding bag show a lower voltage reading than a good quality small shielding bag?
Yes because the metallized layer will absorb the 1000v, over a larger surface area.

Will the sensor detect pin holes in the surface of a shielding bag?
No! because the 1000 volt (HBM) is absorbed by the metal layer of the shielding bag. A shielding bag is an electrical Faraday cage, not a water tight container. A clean cut through a shielding bag when laid flat might not be detected by the sensor. The users visual inspection should identify cuts and holes.

If I cut a big hole out of the back of the bag will the sensor detect it?
Only if the top and bottom sensing discs on Shield-Check are making direct contact with the bag material under test.

When I deliver 1000v (HBM) from the discharge simulator, if the bag is good (less than 10 volts) and shows no voltage reading on the sensor, even through the power LED is on. How do I know than I have carried out a test on that shielding bag.
Less obvious is that the 1000v relay inside the simulator will click, or the bag may move slightly when the change is applied. But to verify both simulator and sensor, remove the sensor from the bag place it on the reference plate and put the discharge probe on the sensors top disc. Then discharge directly, your reading will be in excess of 300 volts.

What if two or more voltage LED's light at the same time?
A spilt signal or (Ringing) has occurred through the bag under test. The sensor receives two or more peak voltage signals at the same time indicating poor shielding.

What Charge remains between the probe and reference plate after the user has taken the previous reading?
When not delivering a pulse, a 10 meg Ohm resistor between the probe and reference plate ensures no residual charge remains.

What if I cut the heat sealed edges off one or both sides of the shielding bag?
The sensor has been designed to check the shielding ability of the bag in it's formed state. Not the ability of the metallized film used to produce the bag. By cutting off the sealed edges you no longer have a bag to measure just the material.

What makes a metallized shielding bag bad?
The nose edge of the bag excessively creased or damaged, the sealed edges of the bag inconsistent, the metallized layer too thin, folds in the bag or snowball effect where the bag has been creased all over.

Why is the voltage sensed nearly always the same if the bag end is open or closed?
The capacitance of the air gap at the open end of the bag is greater than the resistance of the metallized layer around the bag. The 1000 volts will always find the quickest path to Ground/Earth. (In our case the reference plate)

TECHNICAL DESCRIPTION OF SHIELD-CHECK SYSTEM
Shieldcheck provides a quick and convenient check, on the effectiveness of a metallized shielding bags capability to protect its contents against Electro-static Discharge (ESD). A compact sender provides a 1000volt human body model (HBM) discharge which is received by a battery operated sensor unit placed inside the bag. The choice of 1000volt for the test pluse is to avoid break down of the material under test. A bounce free leading edge is achieved by use of a mercury wetted relay.
The sensor unit detects a voltage pulse between its two sensor plates, and remembers the level which has been exceeded displaying it by means of the eight LED display. The nominal levels of detection are as follows.

High speed integrated circuits ensure that fast pulses are registered. DC coupling permits easy checking of the threshold levels.
Shieldcheck and its discharge simulator are based on the EIA541 capacitive probe method. When not delivering a pulse, a 10meg Ohm resistor between the probe and earth reference plate ensures no residual charge remains from previous use. Amongst other Shielding is a function of the resistance around the bag so the pulse amplitude will be dependent on where in the bag the Shieldcheck sensor is placed. When a pulse is delivered, one of the LEDs will light unless the sensor detects less than 10 volts between its plates. This indicates that the peak exceeds the indication but not the next higher value. Thus when the 20volt LED lights, the peak was between 20 and 380volts.

SHIELD-CHECK SC-0-300
Switch on Shield-Check via the right angle switch below part number label.
Make sure the POWER ON LED is visible.
Insert Shield-Check into shielding bag.
When (HBM) Human Body Model pulse has occurred from 1000D Discharge unit the maximum voltage sensed will remain until the operator has pressed the reset switch. (Using a pen or pointed object)
If NO LED has been illuminated this is due to the effective shielding of the bag i.e. 0-9 volts sensed. If a voltage greater than 10 volts has been sensed, one of the eight LEDs will light until reset.
To change batteries unscrew the 4 self tapping screw in the rear of the case. Remove all three batteries CR2032 type, and replace. The + positive of the battery should make contact with the battery clip. The-negative of the battery should make contact with the PCB. Make sure that when not in use the unit is switch OFF.

ESD DISCHARGE SIMULATOR 1000D
Connect appropriate country plug to mains lead. Make sure that the voltage select switch is in the correct position i.e. 120v/240v. The unit has a 100ma fuse located in the rear, to protect against electrical damage. Plug in to mains socket and switch on.
Switch on neon front panel power switch. (Marked ON/OFF)
Connect black test lead in to GND socket, and red test lead into 1000 volts socket using 4mm banana plug ends. Attach stainless steel reference plant to the other end of the black test lead, and attach the small circular probe 30mm high 25mm diameter, to the other end of the Red test lead.
When Shield-Check is in position, make sure that the material under test and Shield-Check are making contact with the reference plate. Place the circular probe on the surface of the bag over Shield-Check sensor plate.
Press the Black discharge button to deliver 1000 Volts (HBM).
Make sure that the operator does not touch the bag under test, the reference plate or stainless steel probe