INFICON PLO-10i User Manual

OPERATION AND SERVICE MANUAL

PLO-10 Series

Phase Lock Oscillator

IPN 605800 Rev. G

OPERATION AND SERVICE MANUAL

PLO-10 Series

Phase Lock Oscillator

IPN 605800 Rev. G

®

www.inficon.com [e-mail]

Due to our continuing program of product improvements, specifications are subject to change without notice.

©2007 INFICON

Trademarks

The trademarks of the products mentioned in this manual are held by the companies that
produce them.

INFICON® is a trademark of INFICON Inc.

All other brand and product names are trademarks or registered trademarks of their respective companies.

Disclaimer

The information contained in this manual is believed to be accurate and reliable. However, INFICON assumes
no responsibility for its use and shall not be liable for any special, incidental, or consequential damages related
to the use of this product.

Disclosure

The disclosure of this information is to assist owners of INFICON equipment to properly operate and maintain
their equipment, and does not constitute the release of rights thereof. Reproduction of this information and
equipment described herein is prohibited without prior written consent from INFICON, Two Technology Place,
East Syracuse, NY 13057-9714. Phone [phone]. See www.inficon.com.

Copyright

©2000 All rights reserved.
Reproduction or adaptation of any part of this document without permission is unlawful.

First Edition, February 2000 Revision A, May 2000 Revision B, October 2000 Revision C, December 2001
Revision D, March 2003 Revision E, February 2005 , Revision F, October 2007, Revision G, November 2007

WARNING

All standard safety procedures associated with the safe
handling of electrical equipment must be observed. Always
disconnect power when working inside the controller. Only
properly trained personnel should attempt to service the
instrument.

Warranty

INFICON warrants the product to be free of functional defects in material and
workmanship and that it will perform in accordance with its published specification
for a period of (twenty-four) 24 months.

The foregoing warranty is subject to the condition that the product be properly
operated in accordance with instructions provided by INFICON or has not been
subjected to improper installation or abuse, misuse, negligence, accident,
corrosion, or damage during shipment.

Purchaser's sole and exclusive remedy under the above warranty is limited to, at
INFICON's option, repair or replacement of defective equipment or return to
purchaser of the original purchase price. Transportation charges must be prepaid
and upon examination by INFICON the equipment must be found not to comply
with the above warranty. In the event that INFICON elects to refund the purchase
price, the equipment shall be the property of INFICON.

This warranty is in lieu of all other warranties, expressed or implied and
constitutes fulfillment of all of INFICON's liabilities to the purchaser. INFICON
does not warrant that the product can be used for any particular purpose other
than that covered by the applicable specifications. INFICON assumes no liability in
any event, for consequential damages, for anticipated or lost profits, incidental
damage of loss of time or other losses incurred by the purchaser or third party in
connection with products covered by this warranty or otherwise.

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Table of Contents

OPERATION AND SERVICE MANUAL..................................................................................................I

1 GENERAL DESCRIPTION.............................................................................................................1-1

1.1 FEATURES.............................................................................................................................. 1-2

1.1.1 VERY WIDE FREQUENCY RANGE................................................................................... 1-2

1.1.2 SUPPORT FOR VERY LOW Q, HIGHLY DAMPED, CRYSTALS......................................1-2

1.1.3 DIRECT REAL TIME MEASUREMENT OF CRYSTAL RESISTANCE..............................1-2

1.1.4 ELECTRODE CAPACITANCE CANCELLATION..............................................................1-2

1.1.5 “AUTOLOCK”.................................................................................................................... 1-2

1.1.6 CRYSTAL FACE ISOLATION (PLO-10i Models only).......................................................1-3

1.2 CHARACTERIZING THE PLO .............................................................................................. 1-3

1.2.1 FREQUENCY ERRORS.......................................................................................................1-3

1.2.2 FREQUENCY ERROR DUE TO PHASE ERROR...............................................................1-3

1.2.3 FREQUENCY ERROR DUE TO IMPERFECT CAPACITANCE CANCELLATION.......... 1-3

1.2.4 CONDUCTANCE ERRORS.................................................................................................1-5

1.3 SPECIFICATIONS ..................................................................................................................1-6

1.4 ACCESSORIES .......................................................................................................................1-7

2 UNDERSTANDING AND SETTING UP THE INFICON PLO-10.............................................2-1

2.1 NORMAL OPERATION .........................................................................................................2-1

2.2 CHECKOUT ............................................................................................................................ 2-1

3 CALCULATING CRYSTAL RESISTANCE.................................................................................3-1

4 ADJUSTING THE CAPACITANCE CANCELLATION.............................................................4-1

4.1 ADJUSTING CAPACITANCE CANCELLATION TRIMMER CAPACITORS................... 4-1

4.2 WORKING WITH VERY LOW Q CRYSTALS ..................................................................... 4-3

5 FREQUENCY ERRORS DUE TO IMPERFECT CAPACITANCE CANCELLATION..........5-1

6 CALCULATING CRYSTAL POWER...........................................................................................6-1

7 CRYSTALS, HOLDERS AND FLOW CELL................................................................................ 7-1

7.1 1 INCH DIAMETER CRYSTALS........................................................................................... 7-1

7.1.1 ELECTRODE CONFIGURATION......................................................................................7-1

7.1.2 CRYSTAL PARAMETERS ...................................................................................................7-2

7.1.3 CRYSTAL SURFACE FINISH............................................................................................. 7-3

7.1.4 CRYSTAL ELECTRODE MATERIALS................................................................................7-3

7.1.5 CRYSTAL THICKNESS.......................................................................................................7-3

7.1.6 MASS SENSITIVITY............................................................................................................7-3

7.1.7 STABILITY...........................................................................................................................7-4

7.1.8 CRYSTAL LIFE EXPECTANCY..........................................................................................7-5

7.1.9 TEMPERATURE COEFFICIENT....................................................................................... 7-5

7.2 CRYSTAL CARE AND HANDLING ..................................................................................... 7-7

7.2.1 CRYSTAL CLEANING......................................................................................................... 7-8

7.2.1.1 General Cleaning ............................................................................................................7-8

7.2.1.2 Organic (hydrocarbon contaminants).............................................................................. 7-8

7.2.1.3 Biomaterials (lipids, proteins and similar biomolecules)................................................ 7-8

7.2.1.4 Lipid vesicles on SiO

7.2.1.5 Polystyrene removal ....................................................................................................... 7-9

7.2.2 ELECTRODE SURFACE MODIFICATIONS..................................................................... 7-9

7.2.2.1 SPIN COATING............................................................................................................. 7-9

7.2.2.2 SELF-ASSEMBLED MONOLAYERS (SAM) ............................................................. 7-9

surfaces....................................................................................... 7-8

2

iv

7.2.2.3 PHYSICAL VACUUM DEPOSITION (PVD) .............................................................. 7-9

7.3 CRYSTAL HOLDERS............................................................................................................. 7-9

7.3.1 HOW TO INSTALL A CRYSTAL IN A INFICON CRYSTAL HOLDER............................. 7-10

7.3.2 HOLDER CARE AND HANDLING...................................................................................7-12

7.3.3 CONSIDERATIONS FOR BUILDING YOUR OWN HOLDER ........................................7-13

7.4 FLOW CELL.......................................................................................................................... 7-13

8 THEORY OF OPERATION............................................................................................................ 8-1

8.1 SAUERBREY EQUATION..................................................................................................... 8-1

8.2 Z-MATCH EQUATION ..........................................................................................................8-2

8.3 THICKNESS CALCULATION............................................................................................... 8-3

8.4 LIQUID MEASUREMENTS................................................................................................... 8-4

8.4.1 DECAY LENGTH OF SHEAR WAVE IN LIQUID..............................................................8-7

8.5 DISSIPATION METHOD........................................................................................................8-8

8.6 ELECTRICAL DESCRIPTION OF THE QUARTZ CRYSTAL............................................. 8-8

8.7 CHARACTERIZING THE CRYSTAL MEASUREMENT................................................... 8-15

8.7.1 FREQUENCY ERRORS.....................................................................................................8-16

8.7.2 FREQUENCY ERROR DUE TO PHASE ERROR.............................................................8-17

8.7.3 FREQUENCY ERROR DUE TO IMPERFECT CAPACITANCE CANCELLATION........ 8-17

8.8 FREQUENCY ERRORS DUE TO IMPERFECT CAPACITANCE CANCELLATION ......8-17

8.9 CALCULATING CRYSTAL POWER.................................................................................. 8-19

9 GLOSSARY....................................................................................................................................... 9-1

10 REFERENCES............................................................................................................................10-1

v

Table of Figures

IGURE 1 EQUIVALENT PHASE ERROR DUE TO IMPERFECT CAPACITANCE CANCELLATION ........................ 1-4

F

FIGURE 2 SYSTEM CONNECTIONS ................................................................................................................ 2-3

FIGURE 3 FRONT CONNECTIONS ..................................................................................................................2-4

FIGURE 4 REAR CONNECTIONS .................................................................................................................... 2-5

FIGURE 5 RESISTANCE VS. CONDUCTANCE VOLTAGE .................................................................................. 3-1

FIGURE 6 CAPACITANCE ADJUSTMENTS....................................................................................................... 4-2

FIGURE 7 FREQUENCY ERROR DUE TO IMPERFECT CAPACITANCE CANCELLATION ..................................... 5-2

FIGURE 8 CRYSTAL POWER DISSIPATION VS. CONDUCTANCE VOLTAGE...................................................... 6-1

FIGURE 9 PLO-10 ASSEMBLY ..................................................................................................................... 6-2

FIGURE 10 INFICON 1" CRYSTAL – ELECTRODE CONFIGURATION ...............................................................7-2

FIGURE 11 INFICON 1" CRYSTAL - AS SEEN FROM THE FRONT SIDE ...........................................................7-2

FIGURE 12 FREQUENCY VS. TEMPERATURE OF INFICON 1" AT-CUT CRYSTAL FOR 90 C ............................ 7-7

FIGURE 13 FREQUENCY VS. TEMPERATURE OF INFICON 1" AT-CUT CRYSTAL FOR 25 C ............................7-7

FIGURE 14 CHC-100 CRYSTAL HOLDER .................................................................................................... 7-10

FIGURE 15 CRYSTAL INSTALLATION .......................................................................................................... 7-11

FIGURE 16 FREQUENCY CHANGE VS. WT % GLYCEROL............................................................................... 8-6

FIGURE 17 RESISTANCE CHANGE VS. WT % GLYCEROL .............................................................................. 8-7

FIGURE 18 CRYSTAL EQUIVALENT CIRCUIT................................................................................................. 8-9

FIGURE 19 POLAR PLOT OF CRYSTAL ADMITTANCE .................................................................................. 8-10

FIGURE 20 ADMITTANCE VS. FREQUENCY, MAGNITUDE AND PHASE OF HIGH Q CRYSTAL ....................... 8-11

FIGURE 21 ADMITTANCE VS. FREQUENCY, REAL AND IMAGINARY COMPONENTS OF HIGH Q CRYSTAL ... 8-11

FIGURE 22 POLAR ADMITTANCE PLOT OF HIGH Q CRYSTAL ..................................................................... 8-12

FIGURE 23 POLAR ADMITTANCE PLOT OF LOW Q CRYSTAL ...................................................................... 8-13

FIGURE 24 ADMITTANCE VS. FREQUENCY, REAL AND IMAGINARY COMPONENTS OF LOW Q CRYSTAL .... 8-13

FIGURE 25 ADMITTANCE VS. FREQUENCY, MAGNITUDE AND PHASE OF LOW Q CRYSTAL ........................ 8-14

FIGURE 26 NON-ZERO PHASE LOCK ...........................................................................................................8-15

FIGURE 27 FREQUENCY ERROR DUE TO IMPERFECT CAPACITANCE CANCELLATION ................................. 8-19

FIGURE 28 CRYSTAL POWER DISSIPATION VS. CRYSTAL RESISTANCE....................................................... 8-20

vi

PLO-10 PHASE LOCK OSCILLATOR

1 GENERAL DESCRIPTION

The INFICON Phase Lock Oscillator was developed specifically to support the use
of the quartz crystal microbalance in the measurement of lossy films and in liquid
applications. In addition to accurately tracking the frequency of heavily damped
crystals, the PLO-10 provides a dc voltage that is proportional to the crystal’s
conductance (1/resistance). This provides additional information in the study of
lossy films and viscous solutions.

The PLO utilizes an internal oscillator referred to as a Voltage Controlled
Oscillator (VCO) to drive the crystal. The crystal current is monitored and the
frequency of the oscillator is adjusted until there is zero phase between the crystal
voltage and current. Assuming that the crystal’s electrode capacitance has been
effectively cancelled, this point of zero phase between the crystal current and
voltage is the exact series resonant point of the crystal. The magnitude of the
current at this point is directly proportional to the crystal’s conductance. This
current is converted to a voltage, demodulated and amplified to create a dc
voltage proportional to crystal conductance.

The PLO contains a phase detector that continuously monitors the phase
difference between the crystal’s current and voltage. At frequencies below the
crystal’s resonant frequency the current leads the voltage and the phase goes to 90
degrees as the frequency separation continues to increase, see Figure 20. Above
the resonant point the current lags the voltage and the phase go to minus 90
degrees. As the frequency increases through the resonant frequency, the phase
goes from plus 90 through 0 to minus 90. It is interesting to note that the phase
angle is 45 degrees when the VCO frequency is one half of the crystal’s
bandwidth above or below the crystal’s resonant frequency.

The output of the phase detector is fed into an integrator. The integrator
accumulates the phase error such that any positive phase error causes the
integrator output to climb; a negative phase causes the integrator output to fall.
With zero phase error the Integrator output holds steady.

The integrator output is connected to the VCO. Thus, if the VCO frequency is
initially below the crystal resonant frequency, the phase will be positive,
producing a positive output at the phase detector. This causes the Integrator
output to climb, which causes the VCO frequency to increase. When the VCO
frequency matches the resonant frequency of the crystal the phase will decrease to
zero, the phase detector output will go to zero, the Integrator output will hold
steady and the VCO frequency will be “locked” to the crystal’s resonant
frequency.

If the crystal’s resonant frequency moves up or down, a phase difference between
the crystal voltage and current will develop, producing a phase detector output.
The non-zero phase detector output will drive the Integrator output up or down
until the phase is zero once again, thus keeping the VCO frequency locked to the
crystal’s resonant frequency.

Once the frequency of the VCO is locked to the series resonant frequency of the

GENERAL DESCRIPTION

1-1

PLO-10 PHASE LOCK OSCILLATOR

crystal, the in-phase component (at zero phase error, there is no out of phase
component) of the crystal current is demodulated to a DC voltage. The amplified
output of the demodulator is provided at the Conductance output.

1.1 FEATURES

1.1.1 VERY WIDE FREQUENCY RANGE

The PLO-10 supports a wide frequency range from 3.8 to over 6 MHz. It will
support both 5 and 6 MHz crystals; and with a low limit of 3.8 MHz it will
support 1.2 MHz of frequency shift on a 5MHz crystal. Also, available is the
PLO-10-2 to support higher frequency crystals. Its frequency range is 5.1 to over
10 MHz.

1.1.2 SUPPORT FOR VERY LOW Q, HIGHLY DAMPED, CRYSTALS

The PLO-10 will reliably lock to crystals with resistance of 5 K or less. In most
cases it will maintain lock up to a resistance of 10 K. It will support crystal
oscillation in highly viscous solutions of more that 88% glycol in water.

1.1.3 DIRECT REAL TIME MEASUREMENT OF CRYSTAL RESISTANCE

The PLO-10 provides a dc voltage output that is proportional to the crystal’s
conductance. Conductance is the inverse of resistance. Based on the measured
conductance output voltage, the crystal resistance is easily calculated.

1.1.4 ELECTRODE CAPACITANCE CANCELLATION

The total quartz crystal impedance includes a shunt capacitance (due to the
capacitance of the crystal electrodes and holder) in parallel with the series
resonant arm. The total current through the crystal is the sum of the current
through the shunt capacitance plus the current through the series resonant arm.
The physical motion of the crystal is reflected in the values of the L, R and C in
the series arm of the crystal only, and therefore we want to subtract out or
otherwise cancel the current through the shunt electrode capacitance. The
INFICON PLO includes a method of canceling the electrode capacitance insuring
that the measured crystal current does not include the current through the
electrode capacitance and therefore is essentially the current through the series
resonant arm of the crystal only.

1.1.5 “AUTOLOCK”

When the PLO-10 loses lock, the VCO is ramped up to the maximum frequency
at which time it is automatically reset to the minimum frequency and a new scan
is initiated.

To insure that the VCO ramps up in frequency, a small amount of quadrature
current is injected into the current to voltage buffer whenever the PLO is
unlocked. This current is equivalent to a shunt capacitance of about 1.5 pfd. As
soon as lock is detected, the quadrature current is turned off.

1-2

GENERAL DESCRIPTION

PLO-10 PHASE LOCK OSCILLATOR

1.1.6 CRYSTAL FACE ISOLATION (PLO-10i Models only)

The PLO-10i Models provide transformer isolation of the crystal front face
electrode. This feature allows user to connect the crystal face to an
electrochemical instrument such as a potentiostat.

1.2 CHARACTERIZING THE PLO

1.2.1 FREQUENCY ERRORS

The first thing we want to know regarding the performance of the PLO, is “What
is the magnitude of the frequency error we can expect from the PLO-10?”

In any oscillator and sensing crystal system, the error in the frequency
measurement, is a function of both the oscillator and the sensing crystal. The
same is true for phase locked loops. Any phase error will introduce a frequency
error and this frequency error will be inversely proportional to the sensing
crystal’s Q. These errors are over and above any change in crystal frequency due
to temperature changes.

There are four important parameters that determine the frequency error of the
PLO and sensing crystal system or indeed, any oscillator and sensing crystal
system. The first two, the zero phase error and the electrode capacitance
cancellation errors, are characteristics of the PLO. The second two are
characteristics of the crystal, the Q of the crystal and the conductance
(1/resistance) of the crystal.

1.2.2 FREQUENCY ERROR DUE TO PHASE ERROR

Given some finite zero phase error, the resulting frequency error depends on the
sensing crystal’s Q, the higher the Q, the lower the error. For phase errors below
10 degrees the frequency error is 0.087 PPM per degree for crystals with a Q of
100,000. Thus a one degree phase error in the PLO results in a 0.44 Hz frequency
error for a 5MHz crystal with a Q of 100,000. For a 5 MHz crystal with a Q of
10,000, the error is 10 time greater or 4.4 Hz per degree.

Frequency Error/degree = df/f = PI/(360*Q)

1.2.3 FREQUENCY ERROR DUE TO IMPERFECT CAPACITANCE CANCELLATION

The effect of imperfect electrode capacitance cancellation can also be viewed as
an equivalent phase error. This error is directly proportional to crystal resistance.
The equivalent phase error due to a non-zero shunt capacitance equal to 1 pfd is
one degree for a crystal with a series resistance of 556 . Since the equivalent
phase error is proportional to the crystal resistance, a 1-pfd residual capacitance
error will result in a 10-degree equivalent error for a sensing crystal with a
resistance of 5.56 K.

GENERAL DESCRIPTION

1-3

PLO-10 PHASE LOCK OSCILLATOR

Polar Plot of Crystal Conductance

Figure 1 Equivalent Phase Error Due to Imperfect Capacitance Cancellation

1-4

GENERAL DESCRIPTION

PLO-10 PHASE LOCK OSCILLATOR

1.2.4 CONDUCTANCE ERRORS

Conductance measurements are meaningful over the range of 0.0001 to 0.04
siemens (a crystal resistance of 10 K to 5 ). Two characteristics of the PLO
limit the range of the conductance measurement. The first is the zero drift of the
demodulator and amplifier and determines the minimum measure-able
conductance. This drift can amount to 0.00005 siemens. The second
characteristic is the non-zero source impedance of the crystal drive voltage. This
source impedance, 20 , appears in series with the crystal resistance and the
conductance output is proportional to the conductance of the crystal and source
combination. The equation for crystal resistance is:

Rcry = (100/Vcond) -20

GENERAL DESCRIPTION

1-5

PLO-10 PHASE LOCK OSCILLATOR

1.3 SPECIFICATIONS

Frequency range: 3.8 to 6.06 MHz, or 5.1 to 10 MHz
Capacitance compensation range: 40 to 200 pfd
Achievable capacitance cancellation:
Crystal conductance range: 0.2 down to 0.0002 siemen
Crystal resistance range:
Phase angle accuracy:
Phase angle stability:
Frequency error vs. phase error and crystal Q: Q= 100,000 0.087 ppm per degree

Conductance output range: 0 to 40 millisiemen
Conductance output scaling: 100 volt/siemen
Conductance output accuracy:
Operating temperature range:
Operating temperature range for stated stability:
Controls: Reset Switch

Indicators: Green “Lock” LED

Crystal Drive Voltage, open circuit: 125 mV rms
Crystal Drive Source Impedance:
Crystal Power: 200 µW, maximum
Crystal Isolation (PLO-10i): Transformer, 25 Vdc maximum
Frequency Output Level: 4 Vp-p
Frequency Output Source Impedance:
Conductance Output Level: 0 to 4 Vdc
Conductance Output Source Impedance:
Power: 12 to 15 Vdc @ 150 mA
Size: 1.6” W x 3.2” H x 4.8” D
Weight (shipping): 3 lbs.

± 0.3 pfd

5 Ω to 5.0 KΩ

± 2 degrees
± 0.5 degrees

Q=10,000 0.87 ppm per degree
Q=1,000 8.7 ppm per degree

± 5 % ±50 microsiemen.
0 to 50°C
20 ± 10°C

Capacitance Adjustment Trimmer,
Course and Fine

Red “Unlock” LED
Yellow “Sweep Rate” LED

20 Ω ± 1%

50 Ω

1 KΩ

1-6

GENERAL DESCRIPTION

PLO-10 PHASE LOCK OSCILLATOR

1.4 ACCESSORIES

Part Number Description

172205

173205 CHC-100 Crystal Holder, CPVC, BNC

184204

828007 Cable, SMB Plug-SMB Plug,1' length,

888023 Adapter, BNC Male to SMB Jack
888026 Adapter, BNC male to binding posts
803081 Power Cord
803312 Capacitance Tuning Tool
900037 Power Supply, 100-250VAC to 12VDC
Refer to INFICON Price List for more accessories and other products.

CHT-100 Crystal Holder, Teflon®, SMB
Connector

Connector
CHK-100 Crystal Holder, Kynar®, SMB

Connector

RG174A/U coax

GENERAL DESCRIPTION

1-7

PLO-10 PHASE LOCK OSCILLATOR

2 UNDERSTANDING AND SETTING UP THE INFICON PLO-10

There are several LED’s on the PLO-10 to indicate its operation.
The green, Lock LED is on when the frequency is locked to a connected crystal’s

resonant frequency.
The Red, Unlock LED will be on whenever the frequency is not locked.
The Yellow, Sweep Rate LED flashes each time the frequency ramp is reset to its low

starting point.
The Reset switch allows you to force the VCO to its lowest frequency independently of

the Integrator output. The Reset switch also forces the Lock LED on, thus turning off the
quadrature current injection. The Quadrature current injection must be off to properly
adjust the capacitance cancellation. To insure that the VCO ramps up in frequency, a
small amount of quadrature current is injected into the current to voltage buffer whenever
the PLO is unlocked. This current is equivalent to a shunt capacitance of about 1.5 pfd.
As soon as lock is detected, the quadrature current is turned off.

2.1 NORMAL OPERATION

The PLO-10 comes set up for operation with a INFICON cable and crystal holder. If a
INFICON cable and crystal holder is being used, then no initial adjustments should be
needed.

During normal operation with a crystal installed and connected to the oscillator, the green
Lock LED will be on and the frequency output will reflect the crystal resonance. The red
Unlock LED will be off.

If the Unlock LED is on, the Sweep Rate LED should slowly flash. Continuous
sweeping of the frequency range indicates that the crystal’s resonant frequency is outside
of the PLO’s frequency range or the crystal’s conductance is below the conductance
threshold.

No flashing of the Sweep Rate LED when the Unlock LED is on can mean one of two
things. First, if the VCO frequency is sitting at its low limit, it means the electrode
capacitance is over compensated. Second, in some cases, even though the crystal
conductance has fallen below the threshold necessary to indicate lock, the internal signals
are still sufficient to keep the VCO locked to the crystal. In that case, the PLO really is
locked and the VCO frequency will be sitting at the crystal frequency somewhere
between its minimum and maximum frequencies.

If the VCO frequency is sitting at its low limit, press and hold the Reset switch and adjust
the fine capacitance trimmer a few degrees clockwise (not more than ten) until the Reset
LED begins to flash.

CHECKOUT

2.2

Make sure the wall mount power supply is specified for the voltage in your lab (120/240
volts).

UNDERSTANDING AND SETTING UP THE INFICON PLO-10

2-1

PLO-10 PHASE LOCK OSCILLATOR

Connect a frequency counter to the Frequency Output.
Connect a voltmeter to the Conductance output. The center conductor on the BNC

connector is positive with respect to ground.
Connect the crystal holder, with a crystal installed, to the PLO by means of the 12-inch

coax cable.
Plug the wall mount power supply into the wall and plug the power plug into the PLO-10.
Refer to Figure 2, Figure 3, and Figure 4 for a complete system connections.
The green, Lock, LED should come on, the frequency should indicate the correct crystal

frequency and the voltmeter should indicate something between 5 millivolts and 4 volts.
Check the capacitance cancellation by pressing and holding the Reset switch. The green,

Lock LED should light. Keeping the Reset switch pressed, adjust the fine capacitance
trimmer clockwise by about 5 degrees. The yellow, Reset LED should flash. Back the
trimmer counterclockwise to the point where the Reset LED just stops flashing. The
capacitance cancellation should be checked and readjusted every time the environment of
the crystal and holder is changed. For example, if the crystal and holder are moved from
air to liquid or liquid to air, the capacitance cancellation should be checked and
readjusted.

Remove the crystal. The red, Unlock, LED should light. The green, Unlock, LED
should go off. The Sweep Rate LED should not flash. If the Sweep Rate LED flashes
the capacitance is under compensated.

2-2

UNDERSTANDING AND SETTING UP THE INFICON PLO-10

PLO-10 PHASE LOCK OSCILLATOR

Figure 2 System Connections

UNDERSTANDING AND SETTING UP THE INFICON PLO-10

2-3

PLO-10 PHASE LOCK OSCILLATOR

Figure 3 Front Connections

2-4

UNDERSTANDING AND SETTING UP THE INFICON PLO-10

PLO-10 PHASE LOCK OSCILLATOR

Figure 4 Rear Connections

UNDERSTANDING AND SETTING UP THE INFICON PLO-10

2-5