ANSI ESD STM-3.1-2006 pdf download ESD Association Standard Test Method for the Protection of Electrostatic Discharge Susceptible Items – Ionization
4.6 Installation Installation should conform to applicable electrical, mechanical and safety codes, as well as individual facility standards. Some equipment, such as compressed gas guns and nozzles may have to meet other requirements such as 29 CFR 1910.95 for noise exposure and 29 CFR 1910.242 for personnel safety with compressed gas devices. Installation techniques should also be applicable to the particular environment in which the ionizer is to be installed (e.g. cleanrooms).
5.0 TEST EQUIPMENT
5.1 The instrument recommended by this standard test method to make performance measurements on air ionization equipment is the CPM (refer to Figure 1). The conductive plate shall be 15 cm by 15 cm (6 inches by 6 inches) with a minimum capacitance of 15 pF when mounted in the test fixture without electrical hookups. The total capacitance of the test circuit, with plate, shall be 20 pF2 pF (refer to Annex B). The instrument recommended by this standard test method may also be used for the periodic verification of air ionizers (refer to ESD SP3.3, Periodic Verification of Air lonizers).
5.2 There shall be no objects, grounded or otherwise, closer than Dimension “A” of the conductive plate except the supporting insulators or plate voltage contacts, as shown in Figure 2 (refer to Annex B).
5.3 The isolated conductive plate, when charged to the desired test voltage, shall not discharge more than 10% of the test voltage within five minutes, in the absence of ionization.
5.4 The voltage on the plate shall be monitored in such a way that the system conforms to Sections 5.1, 5.2 and 5.3. The response time of the monitoring device shall be sufficient to accurately measure changing plate voltages. 5.5 The voltage source used to charge the plate should be current limited so as to meet the requirements of Section 4.1.
6.0 SPECIFIC REQUIREMENTS FOR EQUIPMENT CATEGORIES For the types of ionization equipment listed in Sections 6.1. 6.2.
6.3 and 6.4. the following specific requirements apply:
a) Discharge Time Test – The conductive plate of the test fixture shall be charged to an initial test voltage and allowed to discharge to 10% of the initial test voltage. The time required shall be monitored and recorded for both polarities of initial charge. This time is referred to as the discharge time (refer to Section 5.1 and Figure 1).
b) Offset Voltage Test – The conductive plate shall be momentarily grounded to remove any residual charges and to verify zero of the monitoring device. The plate is then monitored within the ionized environment, per, the procedure described for each equipment category. The resulting observed voltage is referred to as the offset voltage.
c) Locations – The discharge time and offset voltage should be measured for each test location described in the test location figures (see Table 1).