Inficon MPG400, MPG401 Operating Manual

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Operating Manual

Inverted Magnetron Pirani Gauge

MPG400 MPG401

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Product Identification

In all communications with INFICON, please specify the information given on the product nameplate. For convenient reference copy that information into the space provided below:

Validity

Intended Use

Functional Principle

This document applies to products with part number:

MPG400 (FPM sealed) MPG401 (all-metal)

351-010 (DN 25 ISO-KF) 351-020 (DN 25 ISO-KF)

351-011 (DN 40 ISO-KF) 351-021 (DN 40 ISO-KF)

351-012 (DN 40 CF-C) 351-022 (DN 40 CF-C)

The part number (PN) can be taken from the product nameplate.

If not indicated otherwise in the legends, the illustrations in this document correspond to the product with part number 351-010. They apply to the other products by analogy.

We reserve the right to make technical changes without prior notice.

All dimensions in mm.

The Inverted Magnetron Pirani Gauges MPG400 und MPG401 has been designed for vacuum measurement in the pressure range of 5×10

-9

… 1000 mbar.

The Inverted Magnetron Pirani Gauges must not be used for measuring flammable or combustible gases which react in air.

The gauges can be used with an INFICON Controller of the VGC40x / VGC50x series or with another evaluation unit.

Over the whole measuring range, the measuring signal is output as a logarithm of the pressure.

The gauge consists of two separate measuring systems (the Pirani and the cold cathode system according to the inverted magnetron principle). They are combined in such a way that for the user, they behave like one measuring system

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Contents

Product Identification 2 Validity 2 Intended Use 2 Functional Principle 2

1 Safety 4

1.1 Symbols Used 4

1.2 Personnel Qualifications 4

1.3 General Safety Instructions 4

1.4 Liability and Warranty 5

2 Technical Data 6 3 Installation 9

3.1 Vacuum Connection 9

3.1.1 Removing the Magnet Unit (Only for Gauges With CF Flanges) 11

3.2 Electrical Connection 12

3.2.1 Use With an INFICON Controller 12

3.2.2 Use With Another Control Device 12

4 Operation 13

4.1 Measurement Principle, Measuring Behavior 13

5 Deinstallation 15 6 Maintenance 16

6.1 Adjusting the Gauge 16

6.2 Cleaning MPG400, Replacing Parts 18

6.2.1 Disassembling MPG400 18

6.2.2 Cleaning MPG400 19

6.2.3 Reassembling MPG400 20

6.3 Cleaning MPG401, Replacing Parts 21

6.3.1 Disassembling MPG401 22

6.3.2 Cleaning MPG401 23

6.3.3 Reassembling MPG401 24

6.4 Troubleshooting 25

7 Accessories 26 8 Spare Parts 26 9 Returning the Product 28 10 Disposal 28 Appendix 29

A: Measuring Signal vs. Pressure 29 B: Gas Type Dependence 30

ETL Certification 31

For cross-references within this document, the symbol (→  XY) is used.

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1 Safety

1.1 Symbols Used

DANGER

Information on preventing any kind of physical injury.

WARNING

Information on preventing extensive equipment and environmental damage.

1.2 Personnel Qualifications

1.3 General Safety Instructions

Caution

Information on correct handling or use. Disregard can lead to malfunctions or minor equipment damage.

Skilled personnel

All work described in this document may only be carried out by persons who have suitable technical training and the necessary experience or who have been instructed by the end-user of the product.

• Adhere to the applicable regulations and take the necessary precautions for the process media used.

Consider possible reactions between the materials (→  7) and the process media.

Consider possible reactions (e.g. explosion) of the process media due to the heat generated by the product.

• Adhere to the applicable regulations and take the necessary precautions for all work you are going to do and consider the safety instructions in this document.

• Before beginning to work, find out whether any vacuum components are contaminated. Adhere to the relevant regulations and take the necessary precautions when handling contaminated parts.

DANGER

DANGER: magnetic fields

Strong magnetic fields can disturb electronic devices like heart pacemakers or impair their function.

Maintain a safety distance of ≥10 cm between the magnet and the heart pacemaker or prevent the influence of strong magnetic fields by

Communicate the safety instructions to all other users.

antimagnetic shielding.

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1.4 Liabilit y and Warranty

INFICON assumes no liability and the warranty becomes null and void if the enduser or third parties

• disregard the information in this document

• use the product in a non-conforming manner

• make any kind of interventions (modifications, alterations etc.) on the product

• use the product with accessories not listed in the corresponding product

documentation.

The end-user assumes the responsibility in conjunction with the process media

used.

Gauge failures due to contamination, as well as expendable parts (filament), are not covered by the warranty.

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2 Technical Data

Measuring range (air, N2) 5×10-9 … 1000 mbar

Accuracy (N2)

Reproducibility

Gas type dependence

≈±30% in the range 1×10

≈±5% in the range 1×10

→ Appendix B

-8

… 100 mbar

-8

… 100 mbar

Output signal (measuring signal)

Voltage range 0 … +10.5 V

Measuring range 1.82 … 8.6 V

Voltage vs. pressure logarithmic, 0.6 V / decade

(→ Appendix )

Error signal <0.5 V no supply

>9.5 V Pirani measurement element defective (filament rupture)

Output impedance

Minimum loaded impedance

2×10 Ω

10 kΩ, short-circuit proof

Response time (pressure dependent)

p > 10 p = 10

-6

mbar

-8

mbar

<10 ms ≈1000 ms

Gauge identification

85 kΩ referenced to supply common

Status Pin 6

-2

p > 10 Pirani-only mode

p < 10 Cold cathode not ignited

mbar

-2

mbar

Low = 0 V

Pirani-only mode

p < 10-2 mbar Cold cathode ignited

High = 15 … 30 V (dc)

Combined Pirani / cold cathode mode

Lamp High voltage on (LED on)

Supply

DANGER

The gauge may only be connected to power supplies, instruments or control devices that conform to the requirements of a grounded extra-

Supply voltage at the gauge 15.0 … 30.0 V (dc) (ripple ≤ 1 V

Power consumption ≤2 W

Fuse

The minimum voltage of the power supply must be increased proportionally to the length of the sensor cable.

Voltage at the supply unit with maximum line length

INFICON controllers fulfill these requirements.

low voltage (PELV). The connection to the gauge has to be fused1).

≤1 AT

16.0 … 30.0 V (dc) (ripple ≤ 1 V

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)

Adjustment

-4

<HV> potentiometer at <10

mbar

<ATM> potentiometer at atmospheric pressure

Electrical connection FCC68 female, 8 poles

Sensor cable 8 conductors plus shielding

Line length

≤50 m (8×0.14 mm²)

Operating voltage ≤3.3 kV

Operating current ≤500 µA

Grounding concept

Vacuum connection-signal common

→ ("Electrical Connection")

connected via 10 kΩ (max. voltage differential with respect to safety ±50 V with respect to accuracy ±10 V)

Supply common-signal common conducted separately

Materials exposed to vacuum

Vacuum connection Measuring chamber Feedthrough Internal seals MPG400 MPG401 Anode Ignition aid Pirani measuring tube Pirani filament

stainless steel stainless steel ceramic

FPM 75 Ag, Cu, soft solder (Sn, Ag) Mo stainless steel Ni, Au W

Mounting orientation any

Internal volume

≈20 cm³

Pressure ≤10 bar (absolute)

limited to inert gases

Temperatures

Operation

MPG400 MPG401

+5 … +55 °C +5 … +150 °C (at flange in horizontal mounting orientation, without magnetic shielding)

Bakeout +150 °C

(without magnetic shielding and electronics unit)

Pirani filament +120 °C

Storage –40 °C … +65 °C

Relative humidity ≤80% at temperatures up to +31 °C

decreasing to 50% at +40 °C

Use indoors only

altitude up to 2000 m

Degree of protection IP 40

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Dimensions [mm]

MPG400

DN 25 ISO-KF

Weight

351-010 ≈700 g 351-011 ≈720 g 351-012 ≈980 g

ø 63.5

MPG401

105

15.5

DN 40 CF-F

351-020 ≈730 g 351-021 ≈750 g 351-022 ≈1010 g

ø 63.5

18.5

DN 40 ISO-KF

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3 Installation

3.1 Vacuum Connection

DANGER: overpressure in the vacuum system >1 bar

Injury caused by released parts and harm caused by escaping process gases can result if clamps are opened while the vacuum system is pressurized.

Do not open any clamps while the vacuum system is pressurized. Use the type of clamps which are suited to overpressure.

DANGER: overpressure in the vacuum system >2.5 bar

KF flange connections with elastomer seals (e.g. O-rings) cannot withstand such pressures. Process media can thus leak and possibly damage your health.

Use O-rings provided with an outer centering ring.

DANGER

DANGER: protective ground

Products that are not professionally connected to ground can be extremely hazardous in the event of a fault.

The gauge must be electrically connected to the grounded vacuum chamber. The connection must conform to the requirements of protective connection according to EN 61010:

• CF connections fulfill this requirement.

• For gauges with KF connections, use a conductive metallic clam-

ping ring.

Caution: vacuum component

Dirt and damages impair the function of the vacuum component.

When handling vacuum components, take appropriate measures to ensure cleanliness and prevent damages.

Caution: dirt sensitive area

Touching the product or parts thereof with bare hands increases the desorption rate.

Always wear clean, lint-free gloves and use clean tools when working in this area.

DANGER

Caution

WARNING

WARNING: electric arcing

Helium may cause electric arcing with detrimental effects on the electronics of the product.

Before performing any tightness tests put the product out of operation

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and remove the electronics unit.

Procedure

The gauge may be mounted in any orientation. To keep condensates

and particles from getting into the measuring chamber preferably choose a horizontal to upright position and possibly use a seal with a centering ring and filter.

If adjustment should be possible after the gauge has been installed, be

sure to install it so that the <HV> and <ATM> trimmer potentiometers can be accessed with a screw driver (→  16).

Remove the protective lid and install the product to the vacuum system.

When making a CF flange connection, it may be advantageous to temporarily remove the magnet unit (→  11).

Seal with centering ring

Protective lid

Clamp

Seal with centering ring and filter

Keep the protective lid.

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3.1.1 Removing the Magnet Unit (Only for Gauges With CF Flanges)

Tools required

Procedure

• Allen wrench 1.5 mm

• Open-end wrench 7 mm

a) Unfasten the hexagon socket set screw (1) on the electronics unit (2).

b) Remove the electronics unit without twisting it.

c) Unfasten the hexagon head screw (3) on the magnet unit (4) and remove the

magnet unit.

The magnetic force and the tendency to tilt make it difficult to

separate the magnet unit and the measuring chamber (7).

d) Make the flange connection between the gauge and the vacuum system.

e) Remount the magnet unit and lock it with the hexagon head screw (3).

f) Carefully mount the electronics unit (2). (Make sure the pin of the Pirani ele-

ment is properly plugged into the corresponding hole of the electronics unit.)

g) Push the electronics unit up to the mechanical stop and lock it with the hexagon

socket set screw (1).

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3.2 Electrical Connection

Precondition

3.2.1 Use With an INFICON Controller

Make sure the vacuum connection is properly made (→  9).

Connect the sensor cable to the gauge and the controller.

3.2.2 Use With Another Control Device

 Make a sensor cable according to the diagram.

Electrical connection

Pin 1 Supply (15 … 30 V (dc) Pin 2 Supply common Pin 3 Signal output (measuring signal) Pin 4 Identification Pin 5 Signal common Pin 6 Status Pin 7, 8 n.c.

8-pin

FCC-68

connector

 Connect the sensor cable to the gauge and the controller.

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4 Operation

4.1 Measurement Principle, Measuring Behavior

As soon as the required supply voltage is applied, the measuring signal is available between pins 3 and 5. (→ Appendix for the relationship between the measuring signal and the pressure).

Allow for a stabilizing time of approx. 10 min. Once the gauge has been switched on, permanently leave it on irrespective of the pressure.

The gauge consists of tow separate measuring systems (Pirani and cold cathode system according to the inverted magnetron principle). They are combined in such a way that for the user, they behave like one measuring system.

The optimum measuring configuration for the particular pressure range, in which measurement is performed, is used:

10-4 mbar

1000 mbar

Cald cathode Pirani

-2

5×10-9 mbar

• The Pirani measuring circuit is always on

• The cold cathode measuring circuit is controlled by the Pirani circuit and is

activated only at pressures <1×10

-2

The identification output (pin 6) indicates the current status of the gauge:

Pressure Lamp on the

Operating mode Pin 6

gauge

mbar

Gas type dependence

Ignition delay

p > 1×10-2 mbar

p < 1×10-2 mbar

Pirani-only mode Low = 0 V

Cold cathode not ignited

Low = 0 V

Pirani-only mode

p < 1×10-2 mbar

Cold cathode ignited Combined Pirani / cold

High = 15 … 30 VDC

cathode mode

As long as the cold cathode measuring circuit has not ignited, the measuring value of the Pirani is output as measuring signal.

The measuring signal depends on the type of gas being measured. The curves are accurate for dry air, O

, CO and N2. They can be mathematically converted for

other gases (→ Appendix B).

If you are using an INFICON controller, you can enter a calibration factor to correct the pressure reading (→  of that controller).

An ignition delay occurs when cold cathode gauges are switched on. The delay time increases at low pressures and for clean, degassed gauges it is typically:

-5

mbar ≈1 second

-7

mbar ≈20 seconds

10 5×10-9 mbar ≈2 minutes

The ignition is a statistical process. Already a small amount of depositions on the inner surfaces can have a strong influence on it.

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Contamination

As long as the cold cathode measuring circuit has not yet ignited, the measured value of the Pirani is output as measuring signal. The identification output (pin 6, low) indicates the Pirani-only mode.

If the gauge is activated at a pressure p < 3×10-9, the gauge cannot

recognize whether the cold cathode system has ignited.

Once flanged on, permanently leave the gauge in the operating mode

irrespective of the pressure range. Like this, the ignition delay of the cold cathode measuring circuit is always negligible (<1 s), and thermal stabilizing effects are minimized.

Gauge failures due to contamination, as well as expendable parts

(filament), are not covered by the warranty.

Gauge contamination is influenced by the process media used as well as by any present or new contaminants and their respective partial pressures. Continuous operation in the range of 10-4 mbar … 10-2 mbar can cause severe contamination as well as reduced up-time and maintenance cycles. With constantly low pressures (p <1×10

-6

mbar), the gauge can be operated for more than one year without

cleaning (cleaning the gauge →  18, 21).

Contamination of the gauge generally causes a deviation of the measured values:

• In the high pressure range (1×10-3 mbar … 0.1 mbar), the pressure reading is too high (contamination of the Pirani element). Readjustment of the Pirani measuring system →  16.

• In the low pressure range (p < 1×10

-3

mbar), the pressure reading is usually too low (contamination of the cold cathode system). In case of severe contamination, instabilities can occur (layers of the measuring chamber peel off). Contamination due to insulation layers can even lead to a complete failure of the discharge ("Underrange" is displayed).

Contamination can to a certain extent be reduced by:

• geometric protection measures (e.g. screenings, elbows) for particles that spread rectilinearly

• mounting the flange of the gauge at a place where the partial pressure of the pollutants is particularly low.

Special precautions are required for vapors deposited under plasma (of the cold cathode measuring system). It may even be necessary to temporarily switch of the gauge while such vapors occur.

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5 Deinstallation

DANGER: contaminated parts

Contaminated parts can be detrimental to health and environment.

Before beginning to work, find out whether any parts are contaminated. Adhere to the relevant regulations and take the necessary precautions when handling contaminated parts.

DANGER

Procedure

Caution

Caution: vacuum component

Dirt and damages impair the function of the vacuum component.

When handling vacuum components, take appropriate measures to ensure cleanliness and prevent damages.

Caution

Caution: dirt sensitive area

Touching the product or parts thereof with bare hands increases the desorption rate.

Always wear clean, lint-free gloves and use clean tools when working in this area.

 Vent the vacuum system.

 Put the gauge out off operation and unplug the sensor cable.

 Remove the gauge from the vacuum system and install the protective lid.

When deinstalling the CF flange connection, it may be

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advantageous to temporarily remove the magnet unit (→  11).

Protective lid

6 Maintenance

Gauge failures due to contamination, as well as expendable parts

(filament), are not covered by the warranty.

DANGER: contaminated parts

Contaminated parts can be detrimental to health and environment.

Before beginning to work, find out whether any parts are contaminated. Adhere to the relevant regulations and take the necessary precautions when handling contaminated parts.

DANGER

6.1 Adjusting the Gauge

Tools required

Procedure

Caution

Caution: vacuum component

Dirt and damages impair the function of the vacuum component.

When handling vacuum components, take appropriate measures to ensure cleanliness and prevent damages.

Caution

Caution: dirt sensitive area

Touching the product or parts thereof with bare hands increases the desorption rate.

Always wear clean, lint-free gloves and use clean tools when working

The gauge is factory-calibrated. If used under different climatic conditions, through extreme temperatures, aging or contamination, and after exchanging the sensor, the characteristic curve can be offset and readjustment may become necessary

The cold cathode measuring circuit, which is dominant for low pressures (<1×10 the Pirani measuring circuit can be adjusted. Any adjustment has a negligible effect on the pressure range between approx. 10-2 mbar and 102 mbar.

• Screw driver 1.5 mm

• Cylindrical pin ø≈3 mm

in this area.

-3

mbar), is factory-calibrated and cannot be adjusted. By way of contrast,

 If you are using a seal with centering ring and filter, check that they are

clean or replace them if necessary (→  15).

 Put the gauge into operation (if possible, in the position, in which it will be

used later on).

 Evacuate the vacuum system to p << 10

 Turn the nameplate counter-clockwise until the mechanical stop is reached.

-4

mbar, and then wait 10 minutes.

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

While depressing the pin with the cylindrical pin, adjust the <HV>

potentiometer …

… to 4.20 V or … to 5×10

After that, turn the potentiometer

counter-clockwise by 1/3 of a turn.

-4

mbar.

 Vent the gauge with air or nitrogen to atmospheric pressure, and wait at

least 10 minutes.

 Turn the nameplate clockwise until the mechanical stop is reached.



Using the 1.5 mm screwdriver, adjust the <ATM> potentiometer …

… to 8.60 V or … to 1×10

mbar.

 Turn the nameplate back to its original position (it catches).

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6.2 Cleaning MPG400, Replacing Parts

Tools / material required

6.2.1 Disassembling MPG400

DANGER

DANGER: cleaning agents

Cleaning agents can be detrimental to health and environment.

Adhere to the relevant regulations and take the necessary precautions when handling cleaning agents and disposing of them. Consider

• Allen wrench AF 1.5

• Allen wrench AF 3

• Open-end wrench 7 mm

• Pliers for circlip

• Polishing cloth (400 grain) or Scotch-Brite

• Tweezers

• Cleaning alcohol

• Mounting tool for ignition aid

• Ignition aid

• Pirani element (13) incl. FPM seal (13a)

• FPM seal (11) for anode feedthrough

possible reactions with the product materials (→  7).

We recommend replacing the Pirani element when cleaning the gauge.

13a

10a

 Remove the gauge from the vacuum system (→  15).  Unfasten the hexagon socket set screw (1) on the electronics unit (2).  Remove the electronics unit without twisting it.

The cover of the electronics unit cannot be removed.

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6.2.2 Cleaning MPG400

Cleaning the measuring chamber and the polarity insert

 Unfasten the hexagon head screw (3) on the magnet unit (4) and remove

the magnet unit.

The magnetic force and the tendency to tilt make it difficult to

separate the magnet unit and the measuring chamber (7).

 Remove the circlip (5) and the polarity insert (6) from the measuring

chamber

 Remove the three hexagon socket screws (8) incl. lock washers (8a) on the

back of the measuring chamber.

 Carefully remove the following parts in this order (without exerting stress on

the Pirani element (13)): pressure piece (9), complete anode (10), FPM seal (11) incl. support ring (12), Pirani element (13) incl. FPM seal (13a).

The parts can now be cleaned or replaced individually.

 Using a polishing cloth rub the inside walls of the measuring chamber and

the polarity insert to a bright finish.

Cleaning or replacing the anode

The sealing surfaces must only be worked concentrically.

 Rinse the measuring chamber and the polarity insert with cleaning alcohol.  Allow both to dry.

 Remove the used ignition aid (10a) with tweezers.  Using a polishing cloth rub the anode pin to a bright finish.

Do not bend the anode. Do not carry out mechanical work on the

ceramic part.

 Rinse the anode with cleaning alcohol.  Allow the anode to dry.  Insert a new ignition aid (10a) into the mounting tool.  Carefully press the anode (clean or new)

centered and parallel to the tool axis into the ignition aid and insert it to a depth of approx. 15 mm. The final positioning is established after the anode is installed.

Anode Ignition aid

Mounting tool

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Cleaning the Pirani element

Replacing the Pirani element

 Remove the FPM seal (13a) from the Pirani element (13).  Fill the Pirani measuring tube with cleaning alcohol and let it work.  Pour the alcohol out of the tube.  Dry the tube (e.g. with a blow dryer <150 °C).  Slide a new FPM seal over the Pirani element and insert it into the corre-

sponding groove.

 Reinstall the Pirani element (→  20).

If it is severely contaminated or defective.

 Slide a new FPM seal (13a) over the Pirani element (13) and insert it into

the corresponding groove.

6.2.3 Reassembling MPG400

 Mount the Pirani element (→  20).

(→ figure  18)

 Insert the FPM seal (11) with the support ring (12) centered into the

measuring chamber (7). The sealing surface, seal, and ceramic part must be clean.

 Carefully insert the anode (10) incl. ignition aid (10a) into the measuring

chamber.

 Insert the Pirani element (13) with the FPM seal (13a) slid over it into the

corresponding bore hole.

 Carefully place the pressure piece (9) on the measuring chamber and

tighten them with the three hexagon socket screws (8) incl. lock washers (8a) uniformly until the stop position is reached.

 Position the ignition aid (10a) by pushing the mounting tool over the anode

pin until the mechanical stop is reached.

 Blow the particles in the measuring chamber with dry nitrogen (be careful to

hold the measuring chamber with the flange pointing downwards).

 Slide the polarity insert (6) into the measuring chamber until the mechanical

stop is reached.

 Place the circlip (5) snugly fitting on the polarity insert.

Visually check that the anode pin is centered over the middle

hole of the polarity insert (max. eccentricity = 0.5 mm).

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6.3 Cleaning MPG401, Replacing Parts

 If possible perform a leak test (leak rate <10

-9

mbar l/s).

WARNING

WARNING: electric arcing

Helium may cause electric arcing with detrimental effects on the electronics of the product.

Before performing any tightness tests put the product out of operation and remove the electronics unit.

 Mount the magnet unit (4) and lock it with the screw (3).

Carefully mount the electronics unit (2). (Make sure the pin of the Pirani ele-

ment is properly plugged into the corresponding hole of the electronics unit.)

Push the electronics unit up to the mechanical stop and lock it with the

hexagon socket set screw (1).

Adjust the gauge (→  16).

DANGER

DANGER: cleaning agents

Cleaning agents can be detrimental to health and environment.

Adhere to the relevant regulations and take the necessary precautions when handling cleaning agents and disposing of them. Consider possible reactions with the product materials (→  7).

Tools / material required

For cleaning the measuring chamber, the Pirani element must be

removed and replaced.

• Allen wrench AF 1.5

• Allen wrench AF 3

• Open-end wrench AF 6

• Open-end wrench AF 7

• Pliers for circlip

• Polishing cloth (400 grain) or Scotch-Brite

• Tweezers

• Cleaning alcohol

• Mounting tool for ignition aid

• Ignition aid

• Metal seal (11) for anode feedthrough

• Pirani element (13) incl. set of seals (13a, 13b)

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6.3.1 Disassembling MPG401

13a

13b

10a

 Remove the gauge from the vacuum system (→  15).  Unfasten the hexagon socket set screw (1) on the electronics unit (2).  Remove the electronics unit without twisting it.

The cover of the electronics unit cannot be removed.

 Unfasten the hexagon head screw (3) on the magnet unit (4) and remove

the magnet unit.

The magnetic force and the tendency to tilt make it more difficult

to separate the magnet unit and the measuring chamber (7).

 Remove the circlip (5) and the polarity insert (6) from the measuring

chamber.

 Unfasten the hexagon socket set screw (9c) and remove the insulator (9b)

without twisting it.

 Remove the four hexagon socket screws (8) incl. lock washers (8a) on the

back of the measuring chamber.

 Carefully remove the following parts in this order (without exerting stress on

the Pirani element (13)): pressure piece (9), anode extension piece (9a), complete anode (10), metal seal (11) incl. centering ring (12).

 Unfasten the screw fitting (13a) of the Pirani element and remove Pirani ele-

ment together with the copper seal (13b).

The parts can now be cleaned or replaced individually.

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6.3.2 Cleaning MPG401

Cleaning the measuring chamber and the polarity insert

 Using a polishing cloth rub the inside walls of the measuring chamber and

the polarity insert to a bright finish.

Cleaning or replacing the anode

The sealing surfaces must only be worked concentrically.

 Rinse the measuring chamber and the polarity insert with cleaning alcohol.  Allow both to dry.

 Remove the used ignition aid (10a) with pliers.  Using a polishing cloth rub the anode pin to a bright finish.

Do not bend the anode. Do not carry out mechanical work on the

ceramic part.

 Rinse the anode with cleaning alcohol.  Allow the anode to dry.  Insert a new ignition aid (10a) into the mounting tool.  Carefully press the anode (clean or new)

centered and parallel to the tool axis into the ignition aid and insert it to a depth of approx. 15 mm. The final positioning is established after the anode is installed.

Anode Ignition aid

Mounting tool

Replacing the Pirani element

 Slide the screw fitting (13a) and the copper seal (13b) over the Pirani

element (13).

 Mount the Pirani element (→  24).

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6.3.3 Reassembling MPG401

(→ figure  22)

 Insert the Pirani element (13) with the screw fitting (13a) and copper seal

(13b) slid over it into the corresponding conic bore hole (7) of the measuring chamber.

 Tighten the screw fitting (13a) with your fingers while slightly pushing the

Pirani element against the mechanical stop. Then tighten the screw fitting by one turn with the open-end wrench.

 Insert a new metal seal (11) incl. the centering ring (12) centered into the

measuring chamber (7).

 Carefully insert the anode (10) with the ignition aid (10a) and extension

piece (9a) slid onto it into the measuring chamber.

 Carefully place the pressure piece (9) on the measuring chamber.  Insert the four hexagon socket screws (8) incl. lock washers (8a) and

tighten them uniformly until the mechanical stop is reached.

 Carefully slide the insulator (9b) onto the pressure piece (9) and lock it with

the hexagon socket set screw (9c).

 Position the ignition aid (10a) by pushing the mounting tool over the anode

pin until the mechanical stop is reached.

 Blow the particles in the measuring chamber with dry nitrogen (be careful to

hold the measuring chamber with the flange pointing downwards).

 Slide the polarity insert (6) into the measuring chamber until the mechanical

stop is reached.

Place the circlip (5) snugly fitting on the polarity insert.

Visually check that the anode pin is centered over the middle

hole of the polarity insert (max. eccentricity = 0.5 mm).

If possible perform a leak test (leak rate <10-9 mbar l/s). If necessary slightly

retighten the screw fitting (13a).

WARNING

WARNING: electric arcing

Helium may cause electric arcing with detrimental effects on the electronics of the product.

Before performing any tightness tests put the product out of operation and remove the electronics unit.

Mount the magnet unit (4) and lock it with the hexagon head screw (3).

Carefully mount the electronics unit (2). (Make sure the pin of the Pirani ele-

ment is properly plugged into the corresponding hole of the electronics unit.)

Push the electronics unit up to the mechanical stop and lock it with the

hexagon socket set screw (1).

Adjust the gauge (→  16).

tina48e1-c (2017-10) MPG400-401.om

6.4 Troubleshooting

Problem Possible cause Remedy

Measuring signal continually < 0.5 V

No supply voltage. Turn on the power

supply.

"Error low".

Measuring signal continually > 9.5 V "Error high".

Pirani measurement element defective (filament rupture).

Replace the Pirani element (MPG400 →  20) (MPG401 →  23).

Electronics unit not cor-

rectly mounted.

Mount the electronics unit correctly (MPG400 →  20) (MPG401 →  24).

The green lamp is ON and the identification indicates Pirani-only mode (measuring signal continually > 4.0 V).

The cold cathode discharge has not ignited.

Wait until the gas discharge ignites (in case of contamination with insulation layers, the cold cathode may completely fail to ignite). (Cleaning MPG400 →  18 MPG401 →  21).

The MPG has only been

Measuring signal continually > 5 V or display > 10-3 mbar although vacuum pressure is OK.

activated with p < 3×10

Pirani measurement circuit not adjusted, e.g. due to severe contamination.

—9

mbar.

Slightly increase the pressure.

Readjust the Pirani measurement circuit (→  16). If adjustment is impossible, replace the Pirani element.

Measurement of heavy

gases.

Convert with the corresponding formula (→  30).

Severe outgassing in the

cold cathode measuring

Clean the measuring chamber.

chamber.

Measuring signal unstable. Gauge contaminated. Clean the gauge

(MPG400 →  18) (MPG401 →  21).

tina48e1-c (2017-10) MPG400-401.om 25

7 Accessories

8 Spare Parts

MPG400

13a

10a

When ordering accessories, always mention:

• all information on the product nameplate

• description and ordering number according to the accessories list

Description Ordering number

Magnetic shielding BG443155-X

When ordering spare parts, always mention:

• all information on the product nameplate

• description and ordering number according to the spare parts list

Pos. Description Ordering number

12 13a 11 10a

Maintenance kit, consisting of:

1× support ring 1× O-ring FPM ø3.69×1.78 1× O-ring FPM ø10.82× 1.78 3× ignition aid

351-999

13 12 13a 11 10a 10

10a

Repair kit, consisting of:

1× Pirani element 1× support ring 1× O-ring FPM ø3.69×1.78 1× O-ring FPM ø10.82×1.78 3× ignition aid 1× anode, complete

Set of ignition aids, comprising:

10× ignition aid

351-998

351-995

Mounting tool for ignition aid 351-994

Measuring system

DN 25 ISO-KF flange DN 40 ISO-KF flange DN 40 CF-F flange

BN846469-T BN846470-T BN846471-T

tina48e1-c (2017-10) MPG400-401.om

MPG401

13a

13b

10a

Pos. Description Ordering number

11 12 10a

Maintenance set, consisting of:

1× seal HNV 100 (9×1.6) 1× centering ring 3× ignition aid

351-997

1× washer (not used with MPG401)

13 13a 13b 9a 10 10a 11 12

10a

Repair set, consisting of:

1× Pirani element with glass feedthrough 1× screw fitting 1× copper seal 1× anode extension piece 1× anode, complete 3× ignition aid 1× seal HNV 100 (9×1.6) 1× centering ring

Set of ignition aids, consisting of:

10× ignition aid

351-996

351-995

Mounting tool for ignition aid 351-994

Measurement system, complete

DN 25 ISO-KF flange DN 40 ISO-KF flange DN 40 CF-F flange

BN846472-T BN846473-T BN846474-T

tina48e1-c (2017-10) MPG400-401.om 27

9 Returning the Product

WARNING

WARNING: forwarding contaminated products

Contaminated products (e.g. radioactive, toxic, caustic or biological hazard) can be detrimental to health and environment.

Products returned to INFICON should preferably be free of harmful substances. Adhere to the forwarding regulations of all involved countries and forwarding companies and enclose a duly completed

Products that are not clearly declared as "free of harmful substances" are decontaminated at the expense of the customer.

Products not accompanied by a duly completed declaration of contamination are returned to the sender at his own expense.

declaration of contamination (form under www.inficon.com).

10 Disposal

Separating the components

Contaminated components

Other components

DANGER

DANGER: contaminated parts

Contaminated parts can be detrimental to health and environment.

Before beginning to work, find out whether any parts are contaminated. Adhere to the relevant regulations and take the necessary precautions when handling contaminated parts.

WARNING

WARNING: substances detrimental to the environment

Products or parts thereof (mechanical and electric components, operating fluids etc.) can be detrimental to the environment.

Dispose of such substances in accordance with the relevant local

After disassembling the product, separate its components according to the following criteria:

Contaminated components (radioactive, toxic, caustic or biological hazard etc.) must be decontaminated in accordance with the relevant national regulations, separated according to their materials, and disposed of.

Such components must be separated according to their materials and recycled.

regulations.

tina48e1-c (2017-10) MPG400-401.om

Appendix

A: Measuring Signal vs.

Pressure

Conversion formulae

Conversion curves

p = 10

1.667U-d

p U c d

[mbar]

[Torr]

[Pa]

[V] [V] [V]

where p pressure

U measuring signal c, d constant (pressure unit dependent

Pressure p

⇔

6.8

6.875

5.6

U = c + 0.6log10 p

11.33

11.46

9.333

valid in the range 5×10

3.8×10 5×10

-9

mbar < p

-9

Torr < p

-7

Pa < p

<1000 mbar <750 Torr

<1×10

Conversion table

1E+04

1E+02

1E+00

1E–02

1E–04

1E–06

1E–08

underrange

sensor error

0.0

0.5 1.5 2.5 3.5 4.5 5.5 6.5 7.5 8.5

Measuring signal U [V

]

mbar

torr

overrange

9.5 10.5

sensor error

Meas. signal U [V] Pressure p [mbar] Pressure p [Torr] Pressure p [Pa]

<0.5 Sensor error

0.5 … 1.82 Underrange

1.82

2.0

2.6

3.2

3.8

4.4

5.0

5.6

6.2

6.8

7.4

8.0

8.6

5.0×10

1.0×10-8

1.0×10

0.1

1.0

100

1000

-9

-7

-6

-5

-4

-3

-2

3.8×10

7.5×10-9

7.5×10

7.5×10-3

7.5×10

0.75

7.5 75

750

-9

-8

-7

-6

-5

-4

5.0×10

1.0×10-6

1.0×10

0.1

1.0 10

-7

-5

-4

-3

-2

100

1000

1.0×10

8.6 … 9.5 Overrange

9.5 … 10.5 Sensor error (Pirani defective)

tina48e1-c (2017-10) MPG400-401.om 29

B: Gas Type Dependence

Indication range above

-2

mbar

Indication range

-6

… 0.1 mbar

Pressure indicated (gauge calibrated for air).

p (mbar)

8 6

–1

8 6

–2

Water vapor

–3

Indication range above 10

–2

-2

mbar

–1

246824

Pressure indicated (gauge calibrated for air).

p (mbar)

–1

8 6

Indication range

-6

... 10

-1

mbar

Air N

–5

8 2 468 2 46 2 46 2 46

–4

–3

–2

8 6

–3

8 6

–4

8 6

–5

–6

246

H2He Ne

–2

Air

(mbar)

eff

(mbar)

eff

CO Ar

Freon 12 Kr

–1

tina48e1-c (2017-10) MPG400-401.om

Indication range below

-5

mbar

In the range below 10-5 mbar, the pressure indication is linear. For gases other than air, the pressure can be determined by means of a simple conversion formula:

= K × pressure indicated

eff

where gas type K

air (O2, CO, N2) 1.0

Xe 0.4

Kr 0.5

Ar 0.8

2.4

Ne 4.1

He 5.9

These conversion factors are average values.

A mixture of gases and vapors is often involved. In this case,

accurate determination is only possible with a partial pressure measurement instrument, e.g. a quadrupole mass spectrometer.

ETL Certification

RECOGNIZED COMPONENT

3103457

ETL LISTED

The products MPG400 and MPG401

• conform to the UL Standard UL 61010-1

• are certified to the CAN/CSA Standard C22.2 No. 61010-1

tina48e1-c (2017-10) MPG400-401.om 31

LI–9496 Balzers Liechtenstein Tel +423 / 388 3111 Fax +423 / 388 3700

Original: German tina48d1-c (2017-10) reachus@inficon.com

t i na48e1- c

www.inficon.com

Inficon MPG400, MPG401 Operating Manual

Specifications and Main Features

Frequently Asked Questions

User Manual