Products: Electrostatic Voltmeter Sensors & Monitors
Model 542A Series Electrostatic Voltmeter
The Trek Model 542A Electrostatic Voltmeter provides accurate noncontacting measurements of electrostatic surface voltage associated with EOS/ESD sensitive processes.
The microprocessor based Model 542A is ideally suited to monitor critical operations associated with semiconductor, LCD, electronic assembly, and other processes where static charge accumulation poses a threat to production yields or product quality.
A twenty by four (20 x 4) alphanumeric LCD screen displays the present measured voltage, the positive peak voltage value, the negative peak voltage value, and additional menu information. The Model 542A includes independently programmable plus (+) and minus (-) voltage threshold/alarm limits. Audible and visible alarms indicate the detection of surface voltages which meet or exceed the programmed limits.
The Model 542A-1 has a voltage detection and measurement range of 0 to ±10 kV. The Model 542A-2 has a voltage detection and measurement range of 0 to ±20 kV. These models have an exceptional 5% reading accuracy, ±0.2% of full scale, over the probe to surface separation distance of 15 to 30 mm for the Model 542A-1 and 30 to 60 mm for the Model 542A-2.
The Model 542A utilizes a DC stable electrostatic field chopper probe which can be remotely located and easily positioned within process equipment to provide drift-free, highly accurate, noncontacting, spacing independent, voltage measurements in either ionized or non-ionized environments. Two probe types are currently available with the 542A-1 and the 542A-2: a side viewing probe and probe with a 45 degree angle.
In addition, a relay contact output changes state upon threshold detection. This signal can be connected to a process controlling device or other external equipment. A voltage output monitor and an 4-20 mA current loop output can provide additional signal interfacing to facility monitoring equipment. Either an USB port or RS-232 serial port can provide computer based control and monitoring.
PERFORMANCE
Model 542A-1
0 to ±10 kV DC or peak AC.
Model 542A-2
0 to ±20 kV DC or peak AC.
Speed of Response (10% to 90%)
Less than 50 ms for a 1 kV step.Model 542A-1 Accuracy
Better than ±5% of reading. ±0.2% of full scale over the probe-to-surface separation of 15 mm to 30 mm.Model 542A-2 Accuracy
Better than ±5% of reading. ±0.2% of full scale over the probe-to-surface separation of 30 mm to 60 mm.Drift with Time
Less than ±1% of full scale/hour, noncumulative.
PRODUCT FEATURES
The Trek Model 542A Electrostatic voltmeter is microprocessor based and provides accurate noncontacting measurements of electrostatic surface voltage for ESD/EOS sensitive processes in either ionized or nonionized environments. The probes are chopper stabilized for drift-free operation.
- Alphanumeric LCD Display
Twenty character by four line (20 x 4) LCD displays present voltage, and holds the most positive and the most negative measured values.
Alarms
Various alarms (listed below) are activated when the measured voltage exceeds the adjustable threshold limits. Individual threshold limits for positive and negative voltages are independently programmed.
Visual Alarms
LEDs on front panel are illuminated when programmed thresholds are reached.
Audible Alarms
A programmable pulsating or continuous tone. The (+) and (-) alarms have different tone rates for the pulsed tone selection.
Alarm Relay Output
Form C relay contact rated at
175 V, maximum, at 5 watts.
Alarm Digital Output
A TTL output with a TTL low as the alarm “ON” status.
Monitor Output
Model 542A-1
The voltage output is 1/1000th of the measured voltage.
Model 542A-2
The voltage output is 1/2000th of the measured voltage.
Output Noise
Less than 30 mV rms (measured using the true rms feature of the Hewlett Packard Model 34401A digital voltmeter).
Output Impedance
47 ohms.
MENU (Up/Down) Buttons
Used for selecting and programming menu options. These buttons are used to set alarm threshold voltages, alarm conditions, and alarm reset type.ZERO Control
Used to produce zero volts when probe is coupled to a known zero source.
RESET Push Button
Resets the alarms (manual mode) and the Peak Hold display to zero.
Current Output
Provides a current of 4-20 mA that represents measured voltages -10 kV to +10 kV (542A-1) or -20 kV to +20 kV (542A-2).
Serial Port and USB Port
Control specific functions and acquire sensor data from Trek software and a PC computer by connecting into either a rear panel standard computer RS-232 serial port or an USB [Type B] port.
Ground Connection
Banana jack.
PROBES
45° Orientation Type (542P-45D)
Aperture size of 3.8 mm (0.15") diameter.
Dimensions
11 mm dia. x 79 mm L
(0.43" dia. x 3.1" L).
90° (side) Orientation Type (542P-S)
Aperture size of 4 mm (0.156") diameter.
Dimensions
13 mm dia. x 75 mm L
(0.51" dia. x 3" L).
*vacuum application probes available.
Probe Cable Length
5 meters (16 ft), nominal.
Probe-to-Surface Separation (recommended)
Model 542-1 ( 0 to ±10 kV)
15 mm to 30 mm.
Model 542-2 ( 0 to ±20 kV)
30 mm to 60 mm.
ACCESSORIES
- Accessories Supplied
- Operator’s manual
- 6P/4C plug (N9056)
- Serial cable (BA108)
- Software CD-ROM (45833)
- Ground cord (N9044)
- Accessories Available
- In the USA, use the Trek AC/DC Adapter #L5111 or #L5133 (with ground connection). For all other line voltages, contact the factory.
GENERAL
- Dimensions
152 mm W x 87 mm H x 216 mm D
(6" W x 3.4" H x 8.5" D).Weight
0.77 kg (1.7 lb).Power
15 V DC ±20%, 800 mA, power bus or AC/DC adapter with a 2.1 mm DC plug. Positive polarity connected to the center contact.Operating Conditions
Temperature
15 °C to 35 °C.
Relative Humidity
5% to 85%, noncondensing.Power ON/OFF
Rear panel switch.