156A and 156A/1 Charged-Plate Monitor

Is it balanced?

Can you evaluate your ionizers while they are
installed in production?

Is the recording of your ionizer test data
efficient and cost effective?

Use the Model 156A to verify that new ionizers meet your selection criteria.

When evaluating newly setup or active ionizer installations, use the Model 156A to determine if the decay times and ion balance performance are satisfactory for your application.

Use the compact and portable Model 156A to determine when an ionizer needs maintenance.

The Model 156A Charged-Plate Monitor is an important tool for evaluating the performance of the air ionizers used to neutralize static charges.


Tailor the plate size and shape to fit your process

Adjustable START/STOP voltage thresholds for testing very sensitive devices like MR heads


Automate time-consuming testing using computer interface and applications software

Program and Run a Series of Tests

TREK, INC.

11601 Maple Ridge Road

Medina, NY 14103 USA

Call: 1 800 FOR-TREK

Tel: (716) 798-3140
Fax: (716) 798-3106

E-Mail
sales@trekinc.com

Web
www.trekinc.com

The Model 156A tests the efficiency of your ionizer’s ion production by timing how long it takes air ions produced to discharge a floating plate that has been pre-charged to either a positive or negative value. The Model 156A also tests the balance between positive and negative air ions by measuring the offset voltage generated on a floating plate due to an imbalance of positive and negative air ions impinging on the plate from your ionizer.

Typically, as the ionizer ages, the rates of positive and negative air ion production decline. Consequently, the time required for the ionizer to neutralize static charges increases, and the balance of positive and negative air ions changes. The neutralization (decay) time may become too long for the ionizer to fully neutralize charges that are generated at a work location, or the ionizer may begin to charge objects that were initially uncharged. By using the Model 156A to periodically measure the decay times and the ion balance, the need for, and frequency of, ionizer preventative maintenance can be easily determined.

Innovations in Charged-Plate Monitor Technology

The Model 156A uses an innovative voltage-follower technique to provide accuracy, stability, and bandwidth that is unavailable from charged-plate monitors using fieldmeter-based measurement methods.

Accuracy, stability, and low zero offset for balance measurements

Fieldmeter-based charged-plate monitors are only accurate to within a few volts. This inaccuracy is becoming intolerable in many of today's applications, where ion balance is critical. With Trek’s voltage-follower technique, the indicated voltage is within one volt of the actual voltage on the ion collecting plate.

Fieldmeter-based charged-plate monitors also have limited bandwidth, preventing faithful measurement of the ripple from AC ionizers. Trek’s voltage-follower technique has a much higher bandwidth, faithfully revealing these AC signals on the ion collecting plate.

Trek’s voltage-follower technique provides virtually infinite impedance loading of the ion collecting plate, while allowing the plate to be charged and monitored through the same, small diameter cable. Therefore, the size and shape of the ion collecting plate and the plate's capacitance to ground may be tailored to a particular requirement.

For example, the plate capacitance can be matched to the capacitance of a particular ESD-sensitive device, or the plate dimensions can be made to permit placement of the plate in a remote or restricted space. Or, for standard applications, the Model 156P-C150XC150 Ion Collecting Plate is designed with the shape and capacitance-to-ground as specified in ANSI EOS/ESD S3.1.

Tailor the plate size and shape to fit your process

Adjustable START/STOP voltage thresholds for testing very sensitive devices like MR heads

For decay tests, the ion collecting plate is pre-charged to a voltage level above a programmed start voltage for the decay timer.

The time required for incident air ion flow to discharge the ion collecting plate from the programmed start voltage to the programmed stop voltage is measured by the Model 156A. The start and stop voltages for the decay timer are independently programmable to suit your particular testing requirement.

For ionizer balance tests, also known as float tests, the ion collecting plate is initially discharged to zero volts and then allowed to float to the voltage level dictated by incident air ion flow to the ion collecting plate.

The Model 156A is powered by rechargeable batteries that provide over eight hours of operation from a full charge. The Model 156A can also be operated from a line supply using a battery charger/eliminator. Battery operation and the simplicity of the design of the Model 156A make it very reliable, completely portable, and convenient to use.

Automate time-consuming testing using computer interface and applications software

Trek offers a model with a computer interface option, the Model 156A/1. This option adds both a serial communications port and an applications software program to operate the charged-plate monitor from a computer.

Operating the charged-plate monitor from a computer offers several enhancements and advantages over operating the charged-plate monitor from its front panel. These enhancements and advantages include automation of data collection and data storage, accumulation of statistical information, graphic display of the plate voltage in the time domain, report generation, higher resolution of the decay time, and the ability to adjust the start and stop voltage set points in one-volt increments.

Using the applications software, you can perform ion balance tests and decay tests, and can acquire and display data in graphical form to greatly enhance the interpretation of test results. A powerful programming mode allows you to program and run series of ion balance tests and decay tests to automate repetitive tests and data collection.

Model 156A/1 Decay Mode

When the DECAY mode is selected, you can perform positive and negative decay tests to evaluate the ability of the ionizer to neutralize charges on surfaces in the work location. For each decay test, the decay waveform is observable on the analysis panel, and the decay time is given with ten-millisecond resolution when the plate voltage reaches the programmed stop voltage.

Model 156A/1 Ion Balance Mode

When the ION BALANCE mode is selected, you can perform ion balance tests to evaluate the balance of positive and negative air ions. You can specify a test period of any length. The average, minimum, and maximum plate voltages are recorded and displayed for each test period. The changes in plate voltage over time are graphed.

Programming and Running a Series of Tests

It is often necessary to repeat the same series of balance and decay tests on all of the ionizers in your facility, and to record the test results. It is a tremendous aid to be able to automate this work. The applications software for the 156A/1 includes this capability. You can enter a Test Sequence mode to program and execute a series of test steps.

You begin by building a series of ion balance and decay test steps. For each step, you specify the test type (balance or decay), and you are prompted by the program to specify the parameters for each test step. Programming and running a test series is further enhanced with provisions for looping and for programming time delays between test steps.

Editing a series of tests is easy. You identify the test step to be edited, and the program will prompt you to enter new parameters for that step. Unwanted test steps are deleted using a similar method.

Model 156A/1 Report Generators

All saved data is saved as tab-delineated text files that are easily opened using popular spreadsheet software. You are able to record additional notes with the test data. From there, you can manipulate the data as needed for analysis. Test data can also be retrieved and displayed within the applications program.