Monroe Electronics 279L User Manual

INSTRUCTION MANUAL

ISOPROBE® ELECTROSTATIC VOLTMETER

MODEL 279L

110309

P/N 0340177

Accessories Included:

Manual

Line Cord

Probe Cover Plug

100 Housel Ave  PO Box 535 Lyndonville NY 14098 1-800-821-6001 585-765-2254  fax: [phone] monroe-electronics.com

PRODUCT WARRANTY

Monroe Electronics, Inc., warrants to the Owners, this instrument to be free from defects in material and
workmanship for a period of two years after shipment from the factory. This warranty is applicable to the original
purchaser only.

Liability under this warranty is limited to service, adjustment or replacement of defective parts (other than tubes,
fuses or batteries) on any instrument or sub-assembly returned to the factory for this purpose, transportation
prepaid.

This warranty does not apply to instruments or sub-assemblies subjected to abuse, abnormal operating conditions,
or unauthorized repair or modification.

Since Monroe Electronics, Inc. has no control over conditions of use, no warranty is made or implied as to the
suitability of our product for the customer’s intended use.

THIS WARRANTY SET FORTH IN THIS ARTICLE IS EXCLUSIVE AND IN LIEU OF ALL OTHER WARRANTIES
AND REPRESENTATIONS, EXPRESS, IMPLIED OR STATUTORY INCLUDING BUT NOT LIMITED TO THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. Except for obligations expressly undertaken by
Monroe Electronics, in this Warranty, Owner hereby waives and releases all rights, claims and remedies with
respect to any and all guarantees, express, implied, or statutory (including without limitation, the implied warranties
of merchantability and fitness), and including but without being limited to any obligation of Monroe Electronics with
respect to incidental or consequential damages, or damages for loss of use. No agreement or understanding
varying or extending the warranty will be binding upon Monroe Electronics unless in writing signed by a duly
authorized representative of Monroe Electronics.

In the event of a breach of the foregoing warranty, the liability of Monroe Electronics shall be limited to repairing or
replacing the non-conforming goods and/or defective work, and in accordance with the foregoing, Monroe
Electronics shall not be liable for any other damages, either direct or consequential.

RETURN POLICIES AND PROCEDURES FACTORY REPAIR

Return authorization is required for factory repair work. Material being returned to the factory for repair must have a
Return Material Authorization number. To obtain an RMA number, call 585-765-2254 and ask for Customer
Service.

Material returned to the factory for warranty repair should be accompanied by a copy of a dated invoice or bill of
sale, which serves as a proof of purchase for the material. Serial numbers and date codes on our products also
serve to determine warranty status. Removal of these labels or tags may result in voiding a product’s warranty.

Repairs will be returned promptly. Repairs are normally returned to the customer by UPS within 10 to 15 working
days after receipt by Monroe Electronics, Inc. Return (to the customer) UPS charges will be paid by Monroe
Electronics on warranty work. Return (to the customer) UPS charges will be prepaid and added to invoice for out­of-warranty repair work.

RETURN OF REPAIRED ITEMS:

Factory repairs will be returned to the customer by the customer’s choice of FedEx, DHL or UPS. Warranty repairs
will be returned via UPS ground. The customer may request accelerated shipping via the previous mentioned
carriers for both warranty and non-warranty repairs.
repairs will always be at the expense of the customer despite the warranty status of the equipment.

FACTORY REPAIRS TO MODIFIED EQUIPMENT:

Material returned to the factory for repair that has been modified will not be tested unless the nature and purpose of
the modification is understood by us and does not render the equipment untestable at our repair facility. We will
reserve the right to deny service to any modified equipment returned to the factory for repair regardless of the
warranty status of the equipment.

NOTE: Accelerated transportation expenses for all factory

website: www.monroe-electronics.com e-mail: [e-mail]

MODEL 279L

ISOPROBE® ELECTROSTATIC VOLTMETER

TABLE OF CONTENTS

I. SPECIFICATIONS ..........................................................................PAGE 1

II. INSTALLATION .............................................................................. PAGE 3

III. CONTROLS AND INDICATORS ....................................................PAGE 5

IV. OPERATION................................................................................... PAGE 7

V. THEORY .........................................................................................PAGE 8

VI. ADJUSTMENT..............................................................................PAGE 10

VII. TROUBLESHOOTING.................................................................. PAGE 14

APPENDIXES:

MODEL 1034 PROBE MOUNTING..... APPENDIX I……………………….Page 16

POWER ENTRY MODULE..... APPENDIX II………………………………..Page 18

HV BREAKDOWN CONSIDERATIONS.....APPENDIX III………………...Page 20

ACHIEVING SPACING INDEPENDENCE ....APPENDIX IV……………...Page 21

iii

SECTION 1

SPECIFICATIONS

A. Applications:

Model 279L ISOPROBE®ELECTROSTATIC VOLTMETER takes advantage of Monroe’s years of experience in
design of reliable instruments for
modern semiconductor technology. A full spectrum of proven-design interchangeable probes exposes broad new
areas for exploratory research as well as providing a precision instrument for routine applications in electrostatic
measurements. Some typical and potential applications include:

 Disk media research

 IC manufacturing and handling

 Materials evaluation

 Contact potential measurements

 Bioelectric field studies

 Process monitoring and control

B. Features:

 Low profile half rack size for multi-channel applications

NON-CONTACTING measurement of electrostatic potential combined with

 Full complement of interchangeable probes

 Analog recorder output

 LED meter with “blackout switch” for darkroom applications

C. Range:

0 to ±300 volts DC

D. Accuracy:*

0.1% of full scale or 10mV, whichever is greater, 0.003%/C over +20 to +40C range (at recorder
output). Useable to +50

E. Meter resolution:

100mV (4 ½ digit LCD)

F. Speed of response:*

3ms, 10% to 90%, achievable at probe to surface spacing up to 0.1” with low resolution probe.

G. Settling time:

<6½ms to 1% of final value.

C.

H. Frequency response:

Small signal frequency response typically 3db to >300Hz.

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I. Drift:*

<0.01V/hr after 1 hr stabilization (0.003V/hr typical). Not measurably affected by 10C temperature
variation or changes between 10% and 90% relative humidity.

J. Noise:*

<90mV rms referred to input, typical.

K. Surface resolution:

Determined by probe aperture size and surface-probe separation. Standard type 1034E & S probes
with 0.07” (1.75mm) aperture will resolve a 0.10” (2.5mm) spot at 0.02” (0.5mm) separation.

L. Recorder output:

100:1, 3 volts full-scale

M. Output filter:

Bessel low pass filter with 1.2ms constant delay.

N. Size:

1.7 x 8.2 x 15.1 inches (44 x 208 x 384mm), 1.75” rack mounting available (1 or 2 per rack).
Weight 4 lb. (1.8kg).

O. Power requirement:

100, 120, 230 or 240 VAC, 10%, 50/60Hz, 15 watts.

1

/4A SB for 100 & 120 V (Littelfuse 313.250 or equiv.)

Fuse

1

/8A 5x2mm for 230 & 240 V (Littelfuse 217.125 or equiv.)

Fuse

* Dependent on specific probe model, probe-to-surface separation and environment. Specifications shown are for
standard Type 1034E or S probes in a normal laboratory atmosphere. Separation for accuracy and response speed
tests is
environments and may be degraded under exceptionally dirty or dusty conditions or in ambiance of unstable
gaseous constituents.

1

/8” (3mm) and for noise and drift tests, 0.005” (0.13mm). Performance generally improves in controlled

PROBES:

Monroe Electronics Type 1034E (end viewing) or 1034S (side-viewing) probes are 0.35” (9mm) x 0.35” (9mm) x

3.25” (82.6mm) in length. Add 0.8” (20mm) length for cable at minimum bend radius. Contains 1kHz tuning fork
chopping driver and onboard hybrid microcircuit preamp. Useable from -50
configurations are available for high or low resolution and transparent probes for light decay measurements. Length
of probe cable is 10 ft. (3.05 meters). Provision has been made for air or inert gas purging of probe. Standard basic
instrument package includes Model 279L electrostatic voltmeter, line cord and instruction manual. Rear mounted
connector on instrument is standard; front panel connector is optional. Unit is calibrated independent of probe and
includes certificate of NIST traceability. Interchangeable Model 1034 probe (type specified by customer) is sold
separately.

C to +80C. Optional probe

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SECTION 2

INSTALLATION

CAUTION:

Before plugging instrument in, make certain that it is matched to local power line voltage. The factory set line
voltage may be determined by the position of the voltage selector indicator pin in the power entry module. All units
are shipped configured for 120 VAC unless otherwise specified. In the event that it is necessary to change the
operating voltage of the instrument (or inspect or replace the fuses), see Appendix II for more information.

NOTE:

Wire Color Code for Line Cord Provided.

HIGH SIDE OF LINE - BLACK or BROWN

LOW SIDE OF LINE - WHITE or LIGHT BLUE

SAFETY GROUND - GREEN or GREEN/YELLOW

A. Probe mounting:

The 1034 and all other compatible probes must be mounted with the sensitive aperture facing the surface to be
measured.

The probe must be electrically isolated for up to about 400V, since the probe acquires the potential of the surface
being measured.

Further probe mounting information is given in Appendix I.

B. Probe-to-surface spacing:

CAUTION:

When operating at very close probe-to-surface spacing -- BEWARE OF PROBE-TO-SURFACE ARC-OVER and
possible accidental physical contact. Refer to Appendix III for further information.

Probe to surface spacing should be maintained as close as physically reasonable for best performance. Typical
spacing range is from .005” (0.1mm) for unknown voltages below 500 volts to over .125” (3mm) for unknown
voltages up to 3000 volts.

As probe to surface spacing increases instrument performance will suffer:

1. Decreased Accuracy

2. Decreased Speed-of-Response

3. Decreased Surface Resolution

4. Increased Noise

5. Increased Drift

C. System grounding:

The instrument is normally grounded via power cord and the potential measured is referenced to ground. A rear
panel ground connection is provided.

D. Output circuitry:

The output connector is a BNC connector mounted to the rear panel. The output voltage unless otherwise specified
is the measured voltage divided by 100. Normal useable output range is ±3V.

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E. Probe purging:

Probe purging improves instrument performance especially with regard to zero stability, noise and sensitivity to
variations in probe-to-surface spacing. An optional purge kit Model 1017/22G available from Monroe Electronics
maintains an even airflow, reduces temperature variations and filters out dust and other particles.

Contact potential is a function of these variables and should be considered when making any changes in the purging
techniques. Care should be taken to maintain the purged air as free from chemical vapor contamination as
possible.

Probes may also be purged using clean, dry oil-free air from a local source or through the use of dry nitrogen or
other inert gas. Pressure needs only be sufficient to maintain a positive flow of gas out of the sensitive aperture to
prevent foreign materials from entering and, in no case should it exceed ½ psi (14” w.c.). All materials used should
have low out-gassing properties.

For best results, leave purge in continuous operation. For long term storage, cover the end of the probe with the
plastic cap supplied or with aluminum foil to seal against contamination.

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SECTION 3

CONTROLS AND INDICATORS

FRONT PANEL - Figure 3-1

A. STBY/OPER Switch:

This push-push switch controls the operating condition of the unit. So long as power is applied, the following is true:

STANDBY  Starts the probe oscillating but leaves the high voltage disabled.

OPERATE  Activates high voltage only if the probe is plugged in and the tuning fork is oscillating.

B. Display:

The 4½-digit LED display is normally illuminated when power is applied to the unit and acts in a secondary capacity
as a power indicator.

A minus (-) sign at the left side of the display indicates that a negative voltage is being measured and is displayed
approximately 50% of the time (a polarity indecision) when the instrument is properly zeroed while measuring an
input signal of zero. No sign is displayed for a positive input.

The display may be turned off for darkroom use by actuating the push-push display switch through the access hole
in the panel with a suitable tool such as the point of a pen.

C. ZERO 1:

Balances internal probe contact potential to obtain probe to surface spacing insensitivity. This adjustment
procedure is described in Section 4A. ZERO 1 may also be used for large zero offset when spacing insensitivity is
not needed.

D. GAIN:

Closed loop system gain varies with probe to surface spacing. Excessive gain at close spacing causes instability
and insufficient gain at large spacing produces sluggish response and static error.

E. ZERO 2:

Compensates for unwanted system offsets over a range of approximately ±4 volts and does not affect probe to
surface spacing insensitivity. Adjustment procedure is outlined in Section 4. Once set, this operator accessible
adjustment usually does not require further attention except in critical applications.

F. Probe receptacle:

Mates with Model 1034 series probes manufactured by Monroe Electronics. An appropriate and functional probe
must be connected for the instrument to operate.

To connect the probe to the instrument, hold the plug (on probe cable) so that the two arrows are on top. Align with
the receptacle and push straight in until a “click” is heard.

To disconnect, hold the part with the two arrows and pull straight out. This will release the locking device.

Do not connect or disconnect the probe with power applied.

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