MKS 246C Instruction Manual
  1. Manuals
  2. Brands
  3. MKS Manuals
  4. Power Supply
  5. 246C
  6. Instruction manual
MKS 246C Instruction Manual

MKS 246C Instruction Manual

Single channel power supply/readout
Hide thumbs
Table of Contents

Advertisement

Quick Links

120715-P1
Rev A, 2/98
Instruction Manual
MKS Type 246C
Single Channel
Power Supply/Readout
Six Shattuck Road
Fax: (978) 975-0093
Andover, MA 01810-2449
E-mail: mks@mksinst.com
(800) 227-8766 or (978) 975-2350
Web site: http://www.mksinst.com

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the 246C and is the answer not in the manual?

Questions and answers

Related Manuals for MKS 246C

Summary of Contents for MKS 246C

  • Page 1 120715-P1 Rev A, 2/98 Instruction Manual MKS Type 246C Single Channel Power Supply/Readout Six Shattuck Road Fax: (978) 975-0093 Andover, MA 01810-2449 E-mail: mks@mksinst.com (800) 227-8766 or (978) 975-2350 Web site: http://www.mksinst.com...
  • Page 2 MKS sales representative or distributor from which the equipment was purchased or, in the case of a direct purchase from MKS, with the MKS home office in Andover, Massachusetts, USA.
  • Page 3 120715-P1 Rev A, 2/98 MKS Type 246C Single Channel Power Supply/Readout...
  • Page 4 All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, or by any information storage or retrieval system, except as may be expressly permitted in writing by MKS Instruments, Inc.

  • Page 5: Table Of Contents

    Table of Contents Table of Contents Safety Information........................1 Symbols Used in This Instruction Manual..............1 Symbols Found on the Unit ..................2 Safety Procedures and Precautions ................3 Sicherheitshinweise........................ 5 In dieser Betriebsanleitung vorkommende Symbole ........... 5 Am Gerät angebrachte Symbole................. 6 Sicherheitsvorschriften und Vorsichtsmaßnahmen............
  • Page 6 Table of Contents Safety Conditions ..................22 Setup..........................23 Dimensions....................23 Power Requirements ..................25 Mounting Instructions..................25 System Configurations ....................26 Manual Set Point Control................26 External Set Point Control ................28 Remote Flow Control ..................30 Electrical Information....................31 Power Up.......................31 Grounding .....................31 Fuses ......................31 Line Voltage....................32 Connectors .........................33 Interface Connector J9 ...................33 MFC Connector J8..................34 Microjack Connectors ..................35...
  • Page 7 Table of Contents Interface Connector J9................... 42 Flow Out Microjack Connector ..............42 Set Point In/Out Microjack Connector............42 Underside Control...................... 43 Line Voltage Selector Switch ................ 43 Side Panel Control ..................... 43 Decimal Point Selector Dipswitches .............. 43 Gauge Factor Scaling Control ..................44 Scaling Control Factor...................
  • Page 8 Table of Contents Flow Amplifiers.....................70 Internal +5 V Voltage Reference ..............71 Digital Panel Meter..................71 Set Point Buffer and Flow Switching Circuit ..........72 Appendix A: Product Specifications..................73 Appendix B: Model Code Explanation...................75 Model Code .......................75 Appendix C: Gas Correction Factors for Commonly Used Pure Gases ........77 Index ............................81...
  • Page 9 List of Figures and Tables List of Figures and Tables Figures Figure 1: Front Panel Dimensions ..................23 Figure 2: Rear Panel Dimensions................... 23 Figure 3: Side Panel Dimensions................... 24 Figure 4: Internal Set Point Control Setup - Ratio Flow Control..........27 Figure 5: External Set Point Control Setup - Individual Flow Control ........
  • Page 10 List of Figures and Tables viii...

  • Page 11: Safety Information

    Safety Information Safety Information Symbols Used in This Instruction Manual Definitions of WARNING, CAUTION, and NOTE messages used throughout the manual. Warning The WARNING sign denotes a hazard. It calls attention to a procedure, practice, condition, or the like, which, if not correctly performed or adhered to, could result in injury to personnel.

  • Page 12: Symbols Found On The Unit

    Safety Information Symbols Found on the Unit The following table describes symbols that may be found on the unit. Definition of Symbols Found on the Unit Protective earth (ground) Off (Supply) Earth (ground) On (Supply) IEC 417, No.5019 IEC 417, No.5008 IEC 417, No.5017 IEC 417, No.5007 Frame or chassis...

  • Page 13: Safety Procedures And Precautions

    DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT Do not install substitute parts or perform any unauthorized modification to the instrument. Return the instrument to an MKS Calibration and Service Center for service and repair to ensure that all safety features are maintained.
  • Page 14 Safety Information USE THE PROPER POWER SOURCE This product is intended to operate from a power source that does not apply more voltage between the supply conductors, or between either of the supply conductors and ground, than that specified in the manual. USE THE PROPER FUSE Use only a fuse of the correct type, voltage rating, and current rating, as specified for your product.

  • Page 15: Sicherheitshinweise

    Sicherheitshinweise Sicherheitshinweise In dieser Betriebsanleitung vorkommende Symbole Definition der mit WARNUNG!, VORSICHT! und HINWEIS überschriebenen Abschnitte in dieser Betriebsanleitung. Warnung! &CU 5[ODQN 9#4070) YGKUV CWH GKPG )GHCJTGPSWGNNG JKP 'U OCEJV CWH GKPGP #TDGKVUCDNCWH GKPG #TDGKVUYGKUG GKPGP <WUVCPF QFGT GKPG UQPUVKIG )GIGDGPJGKV CWHOGTMUCO FGTGP WPUCEJIGO·­G #WUHÒJTWPI D\Y WPIGPÒIGPFG $GTÒEMUKEJVKIWPI \W -ÌTRGTXGTNGV\WPI HÒJTGP MCPP 8QTUKEJV...

  • Page 16: Am Gerät Angebrachte Symbole

    Sicherheitshinweise Am Gerät angebrachte Symbole Der untenstehenden Tabelle sind die Bedeutungen der Symbole zu entnehmen, die an dem Gerät angebracht sind. Definitionen der am Gerät angebrachten Symbole Ein (Netz) Aus (Netz) Erde Schutzleiter IEC 417, Nr. 5007 IEC 417, Nr. 5008 IEC 417, Nr.

  • Page 17: Sicherheitsvorschriften Und Vorsichtsmaßnahmen

    Bauen Sie in das Instrument keine Ersatzteile ein, und nehmen Sie keine eigenmächtigen Änderungen am Gerät vor! Schicken Sie das Instrument zu Wartungs- und Reparatur-zwecken an einen MKS-Kalibrierungs- und -Kundendienst ein! Dadurch wird sicher-gestellt, daß alle Sicherheitseinrichtungen voll funktionsfähig bleiben.
  • Page 18 Sicherheitshinweise Erdung und Verwendung geeigneter elektrischer Armaturen! In diesem Instrument liegen gefährliche Spannungen an. Alle verwendeten elektrischen Armaturen und Kabel müssen dem angegebenen Typ entsprechen und sich in einwand-freiem Zustand befinden. Alle elektrischen Armaturen sind vorschriftsmäßig anzubringen und zu erden. Richtiges Netzkabel verwenden! Das verwendete Netzkabel muß...

  • Page 19: Informations Relatives À La Sécurité

    Informations relatives à la sécurité Informations relatives à la sécurité Symboles utilisés dans ce manuel d'utilisation Définition des indications AVERTISSEMENT, ATTENTION et REMARQUE utilisées dans ce manuel. #XGTVKUUGOGPV . KPFKECVKQP #8'46+55'/'06 UKIPCNG WP FCPIGT RQVGPVKGN 'NNG GUV FGUVKP¾G ¯ CVVKTGT N CVVGPVKQP UWT WPG RTQE¾FWTG WPG WVKNKUCVKQP WPG UKVWCVKQP QW VQWVG CWVTG EJQUG RT¾UGPVCPV WP TKUSWG FG DNGUUWTG GP ECU F GZ¾EWVKQP KPEQTTGEVG QW FG PQPTGURGEV FGU EQPUKIPGU #VVGPVKQP...

  • Page 20: Symboles Apparaissant Sur L'appareil

    Informations relatives à la sécurité Symboles apparaissant sur l'appareil Le tableau suivant décrit les symboles apparaissant sur l'appareil. Définition des symboles apparaissant sur l'appareil Terre de protection Marche (sous tension) Arrêt (hors tension) Terre (masse) (masse) IEC 417, No. 5007 IEC 417, No.

  • Page 21: Mesures De Sécurité Et Mises En Garde

    NE PAS SUBSTITUER DES PIÈCES OU MODIFIER L'APPAREIL Ne pas utiliser de pièces détachées autres que celles vendues par MKS Instruments, Inc. ou modifier l'appareil sans l'autorisation préalable de MKS Instruments, Inc. Renvoyer l'appareil à...
  • Page 22 Informations relatives à la sécurité Utiliser uniquement un cordon d'alimentation amovible avec des conducteurs dont la section est égale ou supérieure à 0,75 mm . Le cordon d'alimentation doit être approuvé par un organisme compétent tel que VDE, Semko ou SEV. UTILISATION D'UNE ALIMENTATION APPROPRIÉE Cet appareil est conçu pour fonctionner en s'alimentant sur une source de courant électrique n'appliquant pas une tension entre les conducteurs d'alimentation, ou entre les conducteurs...

  • Page 23: Información Sobre Seguridad

    Información sobre seguridad Información sobre seguridad Símbolos usados en el manual de instrucciones Definiciones de los mensajes de ADVERTENCIA, PRECAUCIÓN Y OBSERVACIÓN usados en el manual. #FXGTVGPEKC 'N UÃODQNQ FG #&8'46'0%+# KPFKEC WP TKGUIQ 2QPG FG TGNKGXG WP RTQEGFKOKGPVQ RT±EVKEC EQPFKEKÉP GVE SWG FG PQ TGCNK\CTUG W QDUGTXCTUG EQTTGEVCOGPVG RQFTÃC ECWUCT NGUKQPGU C NQU GORNGCFQU 2TGECWEKÉP...

  • Page 24: Símbolos Que Aparecen En La Unidad

    Información sobre seguridad Símbolos que aparecen en la unidad En la tabla que figura a continuación se indican los símbolos que aparecen en la unidad. Definición de los símbolos que aparecen en la unidad Encendido Apagado (alimentación eléctrica) (alimentación eléctrica) Puesta a tierra Protección a tierra IEC 417, N.°...

  • Page 25: Procedimientos Y Precauciones De Seguridad

    No se debe instalar piezas que no sean originales ni modificar el instrumento sin autorización. Para garantizar que las prestaciones de seguridad se observen en todo momento, enviar el instrumento al Centro de servicio y calibración de MKS cuando sea necesaria su reparación y servicio de mantenimiento.
  • Page 26 Información sobre seguridad USAR EL CABLE ELÉCTRICO ADECUADO Usar únicamente un cable eléctrico que se encuentre en buenas condiciones y que cumpla los requisitos de alimentación de entrada indicados en el manual. Usar únicamente un cable desmontable instalado con conductores que tengan un área de sección transversal equivalente o superior a 0,75mm².

  • Page 27: Chapter One: General Information

    Chapter One: General Information Introduction The MKS Type 246C Single Channel Power Supply/Readout is designed as a power supply/readout and set point source for one analog mass flow controller (MFC). The unit can also power and monitor the flow rate through an analog mass flow meter (MFM).

  • Page 28: How This Manual Is Organized

    Calibration and Service Center before shipping. The ERA Number expedites handling and ensures proper servicing of your instrument. Please refer to the inside of the back cover of this manual for a list of MKS Calibration and Service Centers. Warning All returns to MKS Instruments must be free of harmful, corrosive, radioactive, or toxic materials.

  • Page 29: Chapter Two: Installation

    Chapter Two: Installation How To Unpack the Type 246 Unit MKS has carefully packed the Type 246 unit so that it will reach you in perfect operating order. Upon receiving the unit, however, you should check for defects, cracks, broken connectors, etc., to be certain that damage has not occurred during shipment.

  • Page 30: Interface Cables

    January 1, 1997, some products shipped to the European Community must also comply with the Product Safety Directive 92/59/EEC and Low Voltage Directive 73/23/EEC, which cover general safety practices for design and workmanship. MKS products that meet these requirements are identified by application of the CE mark.

  • Page 31: Generic Shielded Cables

    Table 5: System Interface Cables Generic Shielded Cables MKS offers a full line of cables for all MKS equipment. Should you choose to manufacture your own cables, follow the guidelines listed below: 1. The cable must have an overall metal braided shield, covering all wires. Neither aluminum foil nor spiral shielding will be as effective;...

  • Page 32: Product Location And Requirements

    Product Location and Requirements Chapter Two: Installation Product Location and Requirements The Type 246 unit meets the following criteria: • POLLUTION DEGREE 2 in accordance with IEC 664 • INSTALLATION CATEGORY II, for transient overvoltages, according to EN 61010-1 Operating Environmental Requirements •...

  • Page 33: Setup

    Chapter Two: Installation Setup Setup Dimensions Note All dimensions are listed in inches with millimeters referenced in parentheses. 3.375 (85.7) 3.469 (88.1) Window Figure 1: Front Panel Dimensions 3.00 (76.2) 2.875 (73.0) Window Figure 2: Rear Panel Dimensions...

  • Page 34: Figure 3: Side Panel Dimensions

    Setup Chapter Two: Installation 0.125 12.12 (3.175) (307.9) Cover Screws Cover (4 each side) Front Panel Access to Internal Decimal Point Selector Dipswitches Figure 3: Side Panel Dimensions...

  • Page 35: Power Requirements

    Chapter Two: Installation Setup Power Requirements The power requirements for the 246 unit are: • 115 VAC Setting: 100 to 120 VAC nominal, 50/60 Hz • 230 VAC Setting: 200 to 240 VAC nominal, 50/60 Hz The power consumption for the 246 unit is: •...

  • Page 36: System Configurations

    System Configurations Chapter Two: Installation System Configurations The 246 unit can be configured for manual (internal) set point control, external set point control, or remote operation. All connections are made using the connectors on the rear panel (refer to Figure 8, page 41). The system interface cables are listed in Table 5, page 20. Manual Set Point Control Manual set point control of the flow rate through MFCs is accomplished using either individual 246 units or multiple units connected for ratio operation.

  • Page 37: Figure 4: Internal Set Point Control Setup - Ratio Flow Control

    Chapter Two: Installation System Configurations CB396S-1-2 CB396S-1-2 Window Window Window "Slave" 246 Unit "Slave" 246 Unit "Master" 246 Unit (Channel 2) (Channel 3) (Channel 1) Figure 4: Internal Set Point Control Setup - Ratio Flow Control The flow rate for the first unit in the string (the “master”) is controlled with its front panel SET POINT CONTROL, which is connected to an internal +5 V reference.

  • Page 38: External Set Point Control

    The 246 unit can operate with any controller or pressure transducer provided the signal that enters the 246 unit goes positive with increasing flow (correct polarity). Throughout this manual, the MKS Type 250 Pressure/Flow Controller is used for example only.

  • Page 39: Figure 6: External Set Point Control Setup - Ratio Flow Control

    Chapter Two: Installation System Configurations Ratio Flow Control For ratio flow control, the system requires two or more 246 units connected together, the MFCs, an external pressure controller, a pressure transducer, and the appropriate cables. To connect multiple 246 units together with an external controller (refer to Figure 6): 1.

  • Page 40: Remote Flow Control

    System Configurations Chapter Two: Installation Remote Flow Control Remote flow control can be accomplished using TTL logic control. The MFC Interface connector J8 provides the means to remotely turn the flow on/off and to adjust and monitor the flow rate using a set point signal from an external voltage. Refer to Table 8, page 34, for the MFC Interface connector pinout.

  • Page 41: Electrical Information

    The line fuses protect the internal circuitry; both sides of the line are fused. The fuse values are listed in Table 6. Fuse Information Voltage Setting Fuse Type MKS Part Number 115 VAC 630 mA (T) / 250 V 024-0009 230 VAC...

  • Page 42: Line Voltage

    Electrical Information Chapter Two: Installation Line Voltage The Line Voltage Selector Switch, located on the underside of the 246 unit, configures the unit to accept either 115 or 230 VAC input voltage. The voltage selected is visible through the window in the panel cutout.

  • Page 43: Connectors

    Chapter Two: Installation Connectors Connectors The 246 unit’s two interface connectors and three microjack connectors are located on the rear panel of the unit (refer to Figure 8, page 41). The system interface cables are listed in Table 5, page 20. Interface Connector J9 This 9-pin male Type “D”...

  • Page 44: Mfc Connector J8

    Connectors Chapter Two: Installation MFC Connector J8 This 15-pin female Type “D” connector provides the connection for the mass flow device. The connector provides the necessary power and set point voltages, and receives the flow output signal. MFC Connector J8 Pinout Assignment Description No Connection...

  • Page 45: Microjack Connectors

    Chapter Two: Installation Connectors Microjack Connectors Three microjack connectors are located on the rear panel of the 246 unit (refer to Figure 8, page 41). Flow Out Connector The Flow Out jack is used for data acquisition purposes, or for providing a master flow set point voltage to other slave 246 units.
  • Page 46 Connectors Chapter Two: Installation This page intentionally left blank.

  • Page 47: Chapter Three: Overview

    J10 (flow output). The zero and scaled signal is sent to J9. 2. To the MFC connector J8. This zero-corrected signal is used by MKS flow controllers for comparison against incoming set point voltages. 3. To a second amplifier stage.

  • Page 48: Set Point Signal

    General Information Chapter Three: Overview Set Point Signal The set point circuitry operates independently of the flow circuitry. The source of the set point signal is selected by the three position SET POINT SOURCE SWITCH on the front panel (refer to Figure 7, page 39), as either FLOW, RATIO, or EXT.

  • Page 49: Front Panel Controls

    Chapter Three: Overview Front Panel Controls Front Panel Controls Figure 7 shows the location of the controls on the front panel of the 246 unit. Digital Panel Meter Set Point Flow Control Control Switch Window Set Point Source Zero Control Switch Figure 7: Front Panel Controls Digital Panel Meter...

  • Page 50: Zero Control

    Front Panel Controls Chapter Three: Overview Zero Control This 20-turn potentiometer is used for fine zero adjustment. It has a limited range of ±3% of FS; therefore, larger adjustments must be made with the zero control on the MFC. Set Point Source Switch This 3-position toggle switch selects the source of the set point signal to be sent to the MFC.

  • Page 51: Rear Panel Controls

    Chapter Three: Overview Rear Panel Controls Rear Panel Controls Figure 8 shows the location of the controls on the rear panel of the 246 unit. Flow Out Microjack Connector Set Point In Microjack Connector 9-Pin Male Type "D" Set Point Out Interface Connector J9 Microjack Connector 15-Pin Female Type "D"...

  • Page 52: Fuse Holder

    Rear Panel Controls Chapter Three: Overview Fuse Holder This housing holds the unit’s two fuses. The fuse values are listed in Table 6, page 31. Refer to How To Replace the Fuses, page 67, for more information. Caution Disconnect the AC line cord from the 246 controller before you replace the fuses, to avoid any damage.

  • Page 53: Underside Control

    Chapter Three: Overview Underside Control Underside Control Line Voltage Selector Switch The Line Voltage Selector Switch, located on the underside of the 246 unit, configures the unit to accept either 115 or 230 VAC input voltage. The value of the selected line voltage is visible in the panel cutout.

  • Page 54: Gauge Factor Scaling Control

    Gauge Factor Scaling Control Chapter Three: Overview Gauge Factor Scaling Control There is one Gauge Factor Scaling Control potentiometer on the rear panel of the 246 unit (refer to Figure 8, page 41). This 10-turn potentiometer is used to adjust the full scale voltage signal from the MFC, which corresponds to the flow rate, to a level that enables the digital panel meter (DPM) to display the flow rate directly, in sccm or slm.

  • Page 55: Scaling Control Factor

    Chapter Three: Overview Gauge Factor Scaling Control Scaling Control Factor The Scaling Control Factor is the product of the Gauge Factor for the MFC in use and the Gas Correction Factor for the gas in use: CALING ONTROL ACTOR AUGE ACTOR ORRECTION ACTOR...

  • Page 56: Scaling Control Potentiometer

    Gauge Factor Scaling Control Chapter Three: Overview Scaling Control Potentiometer The Scaling Control (refer to Figure 9) is a 10-turn potentiometer that serves as a voltage divider for the +5 VDC output signal from the MFC; the control has a full scale setting of 1000. Window Outer Control (Sets factors of 100)

  • Page 57: Gas Correction Factor

    T s = 273.15° K (~ equal to 0° C) Note 1. When using the GCF, the accuracy of the flow reading may vary by ±5%, however, the repeatability will remain ±0.2% of FS. 2. All MKS readouts have Gas Correction Adjustment controls to provide direct readout.

  • Page 58: How To Calculate The Gcf For Pure Gases

    Gas Correction Factor Chapter Three: Overview How To Calculate the GCF for Pure Gases To calculate the Gas Correction Factor for pure gases, use the following equation: (0.3106) (s) (d ) (cp ) where: GCF x = Gas Correction Factor for gas X 0.3106 = (Standard Density of nitrogen) (Specific Heat of nitrogen) s = Molecular Structure correction factor where S equals: 1.030 for Monatomic gases...

  • Page 59: How To Calculate The Gcf For Gas Mixtures

    Chapter Three: Overview Gas Correction Factor How To Calculate the GCF for Gas Mixtures For gas mixtures, the calculated Gas Correction Factor is not simply the weighted average of each component’s GCF. Instead, the GCF (relative to nitrogen) is calculated by the following equation: (0.3106) (a s + a s + ...a s ) (a d cp + a d cp + ...a d cp )
  • Page 60 Gas Correction Factor Chapter Three: Overview Example: Calculate the GCF for a gas mixture of argon (gas 1) flowing at 150 sccm and nitrogen (gas 2) flowing at 50 sccm, where: Argon (Ar) Nitrogen (N 150 = 0.75 0.25 1.030 1.000 1.782 g/l 1.250 g/l...

  • Page 61: Labels

    The Serial Number Label, located on the side of the instrument, lists the serial number and the product model code, and displays the CE mark signifying compliance with the European CE regulations. Serial #: 0123456789 Model #: 246C MKS Instruments, Inc. Made in the USA Figure 10: Serial Number Label...
  • Page 62 Labels Chapter Three: Overview This page intentionally left blank.

  • Page 63: Chapter Four: Operation

    Chapter Four: Operation How To Setup the System Chapter Four: Operation How To Setup the System 1. Verify that the LINE VOLTAGE SELECTOR switch on the underside of the 246 unit is set to the proper input voltage, and ensure that the fuse type is appropriate for your voltage setting.
  • Page 64 How To Setup the System Chapter Four: Operation 5. Connect the MFCs to connector J8 on the rear panel of the 246 units in use and, if necessary, connect multiple units together using the proper interface cables. Refer to System Configurations, page 26, for setup information. Note If you are using a 1259A/2259A MFC, do not connect the 2-pin connector to the control valve at this time.
  • Page 65 Chapter Four: Operation How To Setup the System Example: To calculate the Scaling Control Factor for a 20 sccm MFC, which is flowing pure argon gas, multiply the Gauge Factor for argon (200), listed in Table 9, page 45, times the Gas Correction Factor for argon (1.39), listed in Table 12, page 77: CALING ONTROL...

  • Page 66: Figure 11: Gauge Factor Scaling Control Potentiometer - Example Setting

    How To Setup the System Chapter Four: Operation 7. Adjust the GAUGE FACTOR SCALING CONTROL potentiometer for each MFC in use. The Scaling Control potentiometer sets the value of the Scaling Control Factor. Note It is critical for proper system operation that the Scaling Control Potentiometer is set correctly.
  • Page 67 Chapter Four: Operation How To Setup the System 8. Calculate and adjust the SET POINT CONTROL setting for each 246 unit in use. Note The Set Point Control is bypassed when using an external set point voltage for individual gas flow control. If you are using this type of operation, this step is not required.
  • Page 68 How To Setup the System Chapter Four: Operation Example 2: Calculate the Set Point Control setting for a 500 sccm MFC which is flowing pure argon (Ar), if the flow must be maintained at 375 sccm. a. Calculate the desired set point as a percentage of full scale. 375 sccm CALE 500 sccm...
  • Page 69 Chapter Four: Operation How To Setup the System 11. Recheck the DIGITAL PANEL METER on the 246 unit to ensure that it reads 000, ±1 count, as described in step 2, page 53. If you are using a 1259A/2259A MFC: Adjust out any zero offset by the ZERO CONTROL on the MFC.

  • Page 70: Manual Flow Control

    Manual Flow Control Chapter Four: Operation Manual Flow Control Manual (internal) set point control of the flow rate through MFCs is accomplished using either individual 246 units or multiple units connected for ratio operation. In either case, the gas flow is based on the unit’s internal +5 V reference and the unit’s front panel Set Point Control.

  • Page 71: How To Manually Control Ratioed Gas Flows

    Chapter Four: Operation Manual Flow Control How To Manually Control Ratioed Gas Flows This type of operation enables you to control the flow rates of multiple 246 units as a fraction (ratio) of the flow a master 246 unit, using an internal set point signal (refer to Figure 4, page 27).

  • Page 72: External Set Point Control

    External Set Point Control Chapter Four: Operation External Set Point Control External set point control of the flow rate through MFCs is accomplished using either individual 246 units with an external pressure controller, or multiple units connected for ratio operation with an external pressure controller and a pressure transducer.

  • Page 73: How To Control Ratioed Gas Flows With An External Set Point

    The 246 unit can operate with any controller or pressure transducer provided the signal that enters the 246 unit goes positive with increasing flow (correct polarity). Throughout this manual, the MKS Type 250 Pressure/Flow Controller is used for example only.
  • Page 74 External Set Point Control Chapter Four: Operation 3. Plug the controller’s AC LINE CORD into the power line and turn on the power switch. Note Allow the controller to warmup for at least 1½ hours before adjusting the zero. 4. Pump the chamber down below the resolution of the transducer and adjust the zero for a reading of ±0000 on the controller’s digital panel meter (DPM).
  • Page 75 Chapter Four: Operation External Set Point Control 9. Move the CMAE switch on the controller to the AUTO position. Note The controller will vary the pressure control signal to adjust the total flow to achieve the control pressure. Although the total flow rate will change, the ratio between the gases will remain constant.

  • Page 76: Remote Flow Control

    Remote Flow Control Chapter Four: Operation Remote Flow Control Remote control of the flow through MFCs is accomplished using TTL logic control. Interface connector J9 provides the means to remotely turn the flow on and off, and to adjust and monitor the flow rate in any channel using a set point signal from a voltage applied to J9.

  • Page 77: Chapter Five: Maintenance And Troubleshooting

    Instruments immediately. If it is necessary to return the unit to MKS, obtain an ERA number (Equipment Return Authorization Number) from a MKS Service Center before shipping. Please refer to the inside back cover of this manual for a list of MKS Calibration and Service Centers. Maintenance Periodically check for wear on the cables and inspect the enclosure for visible signs of damage.

  • Page 78: Figure 12: Fuse Holder Clip

    Maintenance Chapter Five: Maintenance and Troubleshooting 3. Disconnect all cables from the connectors located on the rear panel of the unit. 4. Insert a small device, such as a flat head screwdriver in the fuse holder clip on the right side of the fuse holder.

  • Page 79: Troubleshooting

    If the supplies output the proper voltages, the problem lies with the 246 unit electronics. If not, the supply itself is faulty. Contact MKS for assistance. 4. Test the 5 V supply at the jumper, or across diode CR1.

  • Page 80: Flow Amplifiers

    J8 to 5.000 Volts. If you cannot achieve the voltage, the problem most likely is with the first stage amplifier (U4A). Contact MKS Instruments for assistance. 2. Check the output of the second amplifier stage (U5). The output should be twice the output voltage measured at pin 10 in connector J8, and at pin 6 in connector J9.

  • Page 81: Internal +5 V Voltage Reference

    The voltage should read between 1.23 and 1.25 Volts. An incorrect input voltage may be caused by a defective reference VR1. An incorrect output may be caused by a defective amplifier U7, also located on the rear of the Main PC board. Contact MKS Instruments for assistance.

  • Page 82: Set Point Buffer And Flow Switching Circuit

    With S2 in the ON state, Q2's gate should be at -15 Volts and drain should be at the set point voltage (measure with high impedance probes). If not, Q2 may be the problem. Contact MKS Instruments for assistance.

  • Page 83: Appendix A: Product Specifications

    Appendix A: Product Specifications Appendix A: Product Specifications CE Compliance EMC Directive 89/336/EEC Electromagnetic Compatibility Low-Voltage Directive 73/23/EEC Low-Voltage Requirements II, according to EN 61010-1 Installation Category 2, according to IEC 664 Pollution Degree Product Safety Directive 92/59/EEC Product Safety and Liability Display Accuracy ±0.1% ±1 digit Flow Display...
  • Page 84 Appendix A: Product Specifications Signal Inputs 0 to +5 VDC (5.5 V maximum) Scaling (GCF) Control 0.1 to 4.0; allows display in actual engineering units for a specific gas External Set Point 0 to 5 VDC (bypasses on-board set point controls) External ON/OFF TTL Compatible Signal Outputs...

  • Page 85: Appendix B: Model Code Explanation

    Appendix B: Model Code Explanation Model Code Appendix B: Model Code Explanation Model Code The model code for the 246 single channel power supply/readout is identified as follows: 246C Type Number (246C) The type number 246C designates the model number of the instrument.
  • Page 86 Model Code Appendix B: Model Code Explanation This page intentionally left blank.

  • Page 87: Appendix C: Gas Correction Factors For Commonly Used Pure Gases

    Appendix C: Gas Correction Factors for Commonly Used Pure Gases Appendix C: Gas Correction Factors for Commonly Used Pure Gases Table 12 lists the gas correction factors for some commonly used pure gases. If the GCF for your gas is not listed, or you are using a gas mixture, you must calculate the GCF. Refer to Gas Correction Factor, page 47, for more information.
  • Page 88 Appendix C: Gas Correction Factors for Commonly Used Pure Gases Gas Correction Factors for Pure Gases (Continued) SYMBOL SPECIFIC HEAT, Cp DENSITY CONVERSION cal/g o C g/l @ 0 o C FACTOR Dichlorofluoromethane CHCl 0.140 4.592 0.42 (Freon - 21) Dichloromethysilane SiCl 0.1882...
  • Page 89 Appendix C: Gas Correction Factors for Commonly Used Pure Gases Gas Correction Factors for Pure Gases (Continued) SYMBOL SPECIFIC HEAT, Cp DENSITY CONVERSION cal/g o C g/l @ 0 o C FACTOR Hydrogen 3.419 0.0899 .- - -2 Hydrogen Bromide 0.0861 3.610 1.00...
  • Page 90 1.32 Empirically defined. Consult MKS Instruments, Inc. for special applications. The GCF for Oxygen is 0.993 when using thermal MFCs such as the Type 1179, 1479, 1679, 1159, and 1259 units, and related products. The GCF for Oxygen is 1.000, as listed in the table, for pressure based MFCs such as the Type 1640, 1150, 1151, 1152, and 1153 units.

  • Page 91: Index

    Index Index description of, 45, 47 gas mixtures, 49 AC line cord, 41 pure gases, 48 reference temperature, 47 Gauge factors, 45, 54 Cables Grounding, 31 generic shielded, 21 system interface, 20 CE mark Installation Category, 22 specifications, 73 Connectors interface J9, 33 Line voltage, 31–32 MFC J8, 34...
  • Page 92 Index Specifications, 73–74 Symbols, definitions of Rear panel controls, 41–43 english, 2 Remote flow control, 30, 66 french, 10 Returning the product, 18, 19 german, 6 spanish, 14 System setup, 53–59 Safety messages, definitions of english, 1 french, 9 Temperature, 22 german, 5 Troubleshooting, 69–72 spanish, 13...

Table of Contents

Save PDF