Category Archives: Operation and Calibration Procedures

Operation and calibration procedures for PHI (Physical Electronics) components

DGC IV calibration

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Years ago RBD Instruments had our DGC IV manufactured by JC Controls.  The DGC IV is basically the same thing as a IG4500.
Although we no longer produce the DGC IV, there are still a few of them in the field.  The calibration procedure is listed below.

 POTENTIOMETERS LIST

PR7(VREF)Reference Voltage Adjust                                                          Direction are with the front

PR4(TC1 Z)TC1 Zero Adjust                                                             of the IG4500 facing you.

PR6(TC2 Z)TC2 Zero Adjust                                                                            N

PR3            TC1 Gain Adjust                                                                                    W –+– E

PR5            TC2 Gain Adjust                                                                                         S

R1(EMIS)    Emission Adjust

PR2(ELEC)Electrometer Adjust

 

Power Supply Tests ( Ground)

  1. Attach Tester box to controller and check voltages on computer or do steps B,C,D,E
  2. Test -15,+15,+5 from 8 Pin Power Connector Pins   2,3,4.
  3. Turn on Ion Gauge
  4. Test +180 V From Grid Pin (Outside) of tube to Ground.
  5. Test +150 V from Grid Pin to Fil Pin (Outside to Inside) of tube.
  6. Check Degas

(1) Reference Voltage Adjustment

  1. Connect DC DVM from R14{E} to ground R31{E}
  2. Turn on IG4500 while holding down the SELECT switch,.
  3. While holding down the SELECT Switch, adjust PR7 (VREF) until the DC voltage is 10.000 ( +/- .001 )
  4. Release Select Switch and Check off Recorder output box
  5. Turn Power off and on, check that all the LED light up, if so check off Digit(LED) Test

(2) TC1 & TC2 Zero Adjustment

  1. Connect TC Cable to TC1 Input on back of IG4500.
  2. Connect a TC tube that is at Atmosphere to the cable.
  3. Connect DC DVM from R26{E} to ground (R31{E})
  4. Adjust PR4(TC1 Z) until DC Voltage is .133 VDC. (+/- .005 )
  5. Do the same with TC2, Using TC2 Input, R33{E} & PR6(TC2 Z).

(3) TC1 & TC2 Gain Adjustment

  1. Connect TC Cable to TC1 Input on Back of IG4500.
  2. Adjust PR3 through the back panel until the main display is the same vacuum as the Test Tube. Because TC Tubes work by Heat, give the tubes time to readjust after the pot is turned.
  3. Do then same with TC2, Using TC2 Input, Bar Graph & PR5.

 

(4) Emission Adjustment

  1. Use tester box or connect a current meter in series with Pin 3 of J1 ( Power Connector ).
  2. Connect IG cable to unit and a IG Test Tube. Connect the current source to the BNC on the unit.
  3. Turn on power and turn on ion gauge tube. Use current source to get to 10 mA range
  4. Adjust PR1 (EMIS) until you get 10.0 mA (+/- .05) on current meter.
  5. Use current source to switch down to 1 mA range, emission should be 1.00mA on current meter, Record current.

(5) Electrometer Adjustment

A. Connect current source to IG4500, set to 1uA. Turn on Ion Gauge.

B. Adjust PR2 (ELEC) so IG4500 displays 1.0-04.

C. Repeat Step B for 1nA=1.0-08, 100pA=1.0-09.

D. Also record for 10pA, it should be 1.0-10. (+/- 2.0)

 

(6) Setpoint & EEPROM

A. Check that the relay turn on and off by listening for them to click

B. Use the computer to set the serial number.

C. Turn unit off and on, Check serial number in “Edit Window” by entering =R#

 

Technical Modes of IG4500

* Enable Adjust Mode

This mode is for turning the System Enables on and off. It is entered by pressing and holding down the [ION] & [SELECT] buttons while turning on the main power . The display will show The Enable Name followed by either On or Off.

IGS Enables

Enable Name Description
F Filament Enable ( Display Mode )
Fd Full Duplex RS-232 Communication
C1 Code 1 enabled – Filament Overdrive
C2 Code 2 enabled – Under Vacuum, No Collector
C3 Code 3 enabled – Over Vacuum
A Averaging Enabled
E Emission Ranging Enabled

 

To Adjust the enables press the [ION] switch to select the different enables and the [DEGAS] switch to change from on to off. The Default for the IG4500 is All enables on.

** Timer and Control Mode

This Mode displays the timer value from the electrometer circuit. The value is a 6 digit Hexadecimal number. To put it on the 5 digit display either the lower 5 or the upper 5 digits will be displayed depending on if the high digit is a 0 or not. The Units LED’s are used as status LED’s

 

Display Unit LED’s

LED Name Status
Torr 25’th Bit of timer
Min Averaging On
mA Full Emission On

 

Mode 8 is entered by turning the Display switch to Emis. , then press the [ION] & [DEGAS] at the same time. The [ION] button will turn the Averaging on & off, you should make sure Averaging is disabled before adjusting it manually or else the controller will probably switch it back. The [DEGAS] button will switch between Full and 1/10 Emission Current.

 

20-622 calibration

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Below are the DR11 commands use in the 20-622 calibration procedure. The 20-622 electron gun control is used on the Physical Electronics 660 scanning auger systems.

Command Structure

Use DR11 program or RBD 147 diagnostics  for computer control.

Function                                               Command/Data (hex)

Beam Voltage                                      1ddd

Emission                                             2ddd

Objective Lens                                     3ddd

Iso. Objective Lens                              4ddd

Obj Y                                                  5ddd

Obj X                                                   6ddd

Cond Y                                               7ddd

Cond X                                                8ddd

Reset Overcurrent                                9ddd

Cond Lens                                           Addd

Notes:    – the command and the data are combined in a 16 bit word

– the left-most digit is most significant in address position and data value

– “d” represents a data value in hex

– 000H = 0, 7FFH = 2047 (mid-scale), FFFH = 4095 (max)

Set the CSR (= 1) for proper communication.

Calibration

 Beam Voltage and Emission

Take the readings from the High Voltage (HV) Programming connector on the back panel. The Beam Voltage reading is taken from pin A and the Emission reading is taken from pin B. The reference is to chassis ground. Note: the bit number in () indicates the only bit set (=1), for troubleshooting purposes.

Command/Data  BV ctrl voltage (V)

1000H                                .001

1100H   (bit 8)                     .625

1200H   (bit 9)                     1.25

1400H   (bit 10)                   2.50

1800H   (bit 11)                   5.00

1C00H                               7.50

1FFFH                              10.00

Check for increasing voltage as you enter the following values in sequence: 1000H, 100FH (bits 0-3), 1010H (bit 4), 1020H (bit 5), 1040H (bit 6), 1080H (bit 7).

Command/Data  Emission ctrl voltage (V)

2000H                                 .001

2100H   (bit 8)                      .625

2200H   (bit 9)                      1.25

2400H   (bit 10)                    2.50

2800H   (bit 11)                    5.00

2C00H                                7.50

2FFFH                               10.00

Check for increasing voltage as you enter the following values in sequence: 2000H, 200FH (bits 0-3), 2010H (bit 4), 2020H (bit 5), 2040H (bit 6), 2080H (bit 7).

Condenser and Objective Lenses

A 200 ohm 2W 10-turn potentiometer must be connected to the Objective Fine Adjustment connector on the back before checking the voltages (Unless it is connected in the electronics bay) . Connect pin D to the pot wiper and connect pins A and C to the pot limits (either order). Set the pot to midway (5 turns for a 10-turn pot).

Note: the bit number in () indicates the only bit set (=1), for troubleshooting purposes. The voltages across the resistors (RX) are taken behind the front panel.

Iso. Objective

 Command/Data  R1-R6 Voltage (V)

4000H                                .016

4100H   (bit 8)                     .304

4200H   (bit 9)                      .610

4400H   (bit 10)                    1.22

4600H                                 1.83

4800H   (bit 11)                     2.44

4A00H                                 3.05

4C00H                                 3.66

4F00H                                 4.58

4FFFH                                 4.88

Check for increasing voltage as you enter the following values in sequence: 4000H, 400FH (bits 0-3), 4010H (bit 4), 4020H (bit 5), 4040H (bit 6), 4080H (bit 7).

Objective

Command/Data  R7-R10 Voltage (V)

3000H                                 .021

3100H   (bit 8)                     .322

3200H   (bit 9)                     .645

3400H   (bit 10)                   1.29

3600H                                1.94

3800H   (bit 11)                   2.58

3A00H                               3.23

3C00H                               3.88

3F00H                               4.85

3FFFH                              5.17

Check for increasing voltage as you enter the following values in sequence: 3000H, 300FH (bits 0-3), 3010H (bit 4), 3020H (bit 5), 3040H (bit 6), 3080H (bit 7).

Condenser

Command/Data  R11-R14 Voltage (V)

A000H                                 .018

A100H (bit 8)                       .469

A200H   (bit 9)                     .939

A400H   (bit 10)                   1.88

A600H                                 2.82

A800H   (bit 11)                     3.76

AA00H                                  4.70

AC00H                                  5.64

AF00H                                  7.05

AFFFH                                  7.50

Check for increasing voltage as you enter the following values in sequence: A000H, A00FH (bits 0-3), A010H (bit 4), A020H (bit 5), A040H (bit 6), A080H (bit 7).

Steering

Check for proper centering of the voltages at the Objective and Condenser Steering connector on the back panel.

Command/Data  Between pins, Voltage (V)

57FFH                                   F&H, 0V +/- .4V                  Obj. Y

67FFH                                   E&G, 0V +/- .4V                  Obj. X

77FFH                                   B&D, 0V +/- .4V                  Cond. Y

87FFH                                   A&C, 0V +/- .4V                  Cond. X

20-622 System Test

It is possible for a 20-620 or 20-622 to work on the bench but not focus properly on a system. That is because on the bench the Objective and ISO Objective supplies are tested separately but on the system the objective coil is actually two coils which are tied together. So one of the objective supplies may cave in when connected to the objective coil. You can do a quick test by measuring the voltage across the current resistors behind the front panel of the 20-622 or 20-620.

Voltages for the 20-622 are listed below. The 20-620 should show a similar trend.

20-622   3kV Beam voltage, COND set to 35%, OBJ set to 74.49%, and Objective fine pot set to midrange.

COND.856
OBJ3.68
ISO OBJ3.69

20-622   5kV Beam voltage, COND set to 35%, OBJ set to 83.49%, and Objective fine pot set to midrange.

COND1.076
OBJ3.85
ISO OBJ3.47

20-622 Coil voltage supply test points

There are three coil voltage supplies in the 20-622:

Condenser 30V DC

Objective 34.5V DC

Isolated Objective 40V DC

To measure the supplies, remove the 4 screws on the 20-622 front panel and drop the front panel down (it is on a hinge).

There are three fuses visible on the front center of the heat sink assembly.

The top fuse is the Condenser supply, and it has a value of 1.5A slow blow.  Measure from either side of the fuse to the chassis and there should be approximately 30 V DC when the 20-622 main power is turned ON.

The center fuse is the Objective supply, and it has a value of 2A slow blow.  Measure from either side of the fuse to the chassis and there should be approximately 34.5 V DC when the 20-622 main power is turned ON.

The bottom fuse is the isolated Objective supply, and it has a value of 2.5A slow blow.  Measure from either side of the fuse to the ISO Objective test point (white wire) near the far-right hand current sense resistors. There be approximately 40 V DC when the 20-622 main power is turned ON.

The picture below shows the ISO Objective test point location.

ISO obj test point 20-622
ISO obj test point 20-622
Lens voltage supplies schematic
Lens voltage supplies schematic
20-622 OBJ Fine Jumper pins

72-100 voltage

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I recently encountered an unusual problem on two different 660 scanning auger systems within a period of a few months where the 72-100 multiplier voltage would drop off after a period of time.

On one system the 97 SED preamp would fail after a few minutes of warm up time, resulting in no image. On the other system the 96A V/F preamplifier would fail after 20 to 30 minutes, resulting in no AES data.

In both cases I measured the multiplier supply voltages at the preamp and the voltages were there when functioning and not there or unstable when in the failed mode. So easy enough, that should be a problem on the 72-100 board. To verify that the problem was on the board I swapped the 72-100 board with the other one. For those of you not familiar with the 660 scanning auger system or the 72-100 electron multiplier supply, there are two 72-100s on a 660. One is for the CMA AES analyzer and the other one is for the 97 SED preamplifier. The boards are identical and can be swapped out by physically moving the boards and changing an address switch.

Swapping the 72-100 boards produced the same result. That meant that the problem was not on the board, so the next most likely thing was the SHV multiplier supply cable. Those cables checked out fine with an ohmmeter but to be sure I also swapped the cables out and the problem was still there.

So as unlikely as it was, the only thing left was the 72-100 mother board.   I pulled out the mother board looking for a bent pin or something that could explain the problem and did in fact find that one of the 1K ohm filter resistors was out of spec and looked like it had been running hot. Moving it slightly caused the resistor to break in two.

Here is a picture of the motherboard that shows the resistor:

72-100 R1 R2

72-100 R1 R2

And here is the schematic that shows both resistors:

72-100 mother board schematic

72-100 mother board schematic

Replacing the defective resistor solved the problem. What was interesting for me with this problem was that in over 37 years of working with PHI surface analysis systems I had never seen this problem before, and then I saw the same problem on two different systems within a short period of time.

If you have an intermittent SED image or AES data problem on your 660 (or 4000 series) scanning auger system, keep this solution in mind as something to check.