PERFORMANCE

All specifications are with a Model PD1216P probe with a probe-to-surface separation of 0.4 mm.

Measurement Range
0 to ±40 V DC or peak AC.

Sensitivity
1 mV.

Accuracy
Voltage Monitor Output
Better than ±0.05% of full scale.
Voltage Display
Better than or equal to ±2 counts,
referred to the voltage monitor.

Speed of Response (10% to 90%)
At Fastest Speed Setting
Less than 3 ms for a 10 V step.
At Slowest Speed Setting
Less than 5 ms for a 10 V step.

Noise (typical)
Less than 1 mV rms,
referenced to measured voltage.

Stability
Drift with Time
Less than 50 ppm/hour, noncumulative.
Drift with Temperature
1:1 monitor output
Less than 50 ppm/°C.
10:1 monitor output
Less than 100 ppm/°C.

PROBE

During operation, the metallic surfaces of the probe are driven to voltage levels equal to the measured surface voltage value. A probe holding fixture, should be of a insulating material with dissipative properties (10⁷ to 10¹¹ Ω/square) to prevent shorting of the probe to ground. Phenolic or other dissipative type material is recommended to avoid any fixture material charge retention.

Recommended Probe-to-Surface Separation
0.2 mm to 2 mm.

Model PD1216P Sensor Probe
Aperture Orientation
Side viewing.
Aperture Size
4.6 mm (0.18").
Probe Body Type
Round body.
Dimensions
10 mm Diameter x 56 mm L
(0.4" Diameter x 2" L).

Probe Cable Length
2743 mm ±127 mm (9 ft. ±5").

PRODUCT FEATURES

Null Voltage Source
A calibrated 10-turn dial representing a 10 volt supply, with switch selectable polarity is used to produce zero volts output when the probe is coupled to a known zero volt surface. Also used to null contact potentials on surfaces relative to the probe’s gold sensitive electrode as a reference.
Range
±10 volts
Accuracy
1%
Resolution
10 mV.

Voltage Display
3½ digit LED display.
Range
Switch selectable for ±10 V or ±40 V full scale.
Resolution 10 V Range
0.01 V.
Resolution 40 V Range
0.1 V.
Zero Offset
±2 counts, referred to the voltage monitor.
Sampling Rate
3 readings per second.

Voltage Monitor Output (1:1)
A buffered 0 to ±40 V BNC output provides a replica of the measured voltage.
Scale
1:1 of the measured voltage.
Output Noise
Less than 1 mV rms (measured using the true rms feature of the Hewlett Packard Model 34401A digital multimeter).
Output Current
5 mA.
Output Impedance
100 Ω, nominal.

Voltage Monitor Output (10:1)
A buffered 0 to ±4 V BNC output provides a low voltage
replica of the measured voltage.
Scale
10:1 of the measured voltage.
Output Current
5 mA minimum.
Output Impedance
0.1 Ω, nominal.

Response Speed Control
A front panel potentiometer that adjusts the AC response of the Model 325.

Drift/Spacing Null Adjustment
This back panel adjustment minimizes the variation in monitored voltage values as the probe to test surface spacing changes.

GENERAL

Dimensions
108 mm H x 223 mm W x 370 mm D
(4.25" H x 8.75" W x 14.5" L).

Weight
3.6 kg (8 lb).

Voltage Monitor Connectors
BNC coaxial connectors.

Ground Receptacle
Banana jack.

AC Line Cord Receptacle
Standard three-prong line cord with integral fuse holder.

Power Switch
A rear panel power ON/OFF rocker switch.

Line Supply
90 to 127 V AC at 48 to 63 Hz
(optionally available at 180 to 250 V AC at 48 to 63 Hz).

Operating Conditions
Temperature
0 °C to 40 °C.
Relative Humidity
To 85%, noncondensing.

CERTIFICATION

TREK, INC. certifies that each Model 325 is tested and calibrated to specifications using measurement equipment traceable to the National Institute of Standards and Technology or traceable to consensus standards.
Low Voltage Safety Compliance
(EN 61010-1)
Overvoltage Category
CAT II: Local-level mains, appliances, portable equipment.
Pollution Category
Degree 1: Operate in environments where no pollution or only dry nonconductive pollution occurs.

All specifications are subject to change.