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Related Manuals for MKS HPS 947 Series
Summary of Contents for MKS HPS 947 Series
- Page 1 ® Series 947 Digital Convection Enhanced Pirani (CEP) Vacuum Sensor System OPERATION AND MAINTENANCE MANUAL...
- Page 3 ® SensaVac Series 947 Digital Convection Enhanced Pirani (CEP) Vacuum Sensor System February 1999 Part # REV.A ® Products Series 947 CEP System...
- Page 4 303-442-6880 © 1996 by MKS Instruments, Inc. HPS ® Division. All rights reserved. SensaVac is a registered trademark of MKS Instruments, Inc. Teflon and Viton are registered trademarks of DuPont Co. VCR is a registered trademark of Cajon Co. ®...
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Page 5: Table Of Contents
Table of Contents Table of Contents Package Contents ..............1 Symbols Used in this Manual ............ 2 Safety Precautions ..............3 Specifications ................5 Controller ..................6 Sensor Tube .................. 7 Feature and Control Locations ..........8 Typical Applications for the Series 947 CEP System ....9 About the SensaVac ®... - Page 6 Leak Detection ................19 Using the Series 947 CEP System with Other Gases ..... 22 Nitrogen Equivalent Pressure ............. 22 Calibrating for Other Gases ............23 Maintaining the Series 947 CEP System ........ 24 Troubleshooting and Service ............24 Cleaning the Series 947 CEP Controller Front Panel ....24 Cleaning the CEP Sensor ............
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Page 7: Package Contents
Package Contents Before unpacking your Series 947 Digital Convection Enhanced Pirani (CEP) Vacuum Sensor System, check all surfaces of the packing material for shipping damage. Please be sure that your Series 947 CEP System package contains these items: 1 Series 947 CEP Controller 1 female, 9-pin, subminiature D (D-sub) Accessory connector 1 power cord 1 SensaVac... -
Page 8: Symbols Used In This Manual
Symbols Used in this Manual The first two symbols below, located on your Series 947 Controller and/or Sensor, identify critical safety concerns. They are used throughout this manual to further define the safety concerns associated with the product. The last two symbols identify other information in this manual that is essential to highlight or useful in achieving optimal performance from your Series 947 CEP System. -
Page 9: Safety Precautions
Safety Precautions Do not use the Series 947 CEP System's Sensor with explosive gas mixtures or gases that are combustible in air. If the control circuit fails or an exothermic catalytic reaction occurs at the sensor platinum wire, the wire could ignite the gas mixture. When using the Series 947 CEP System with gases other than air or nitrogen, avoid overpressure to prevent any possibility of explosion. - Page 10 VDE, Semko, or SEV. The Series 947 CEP System and all its accessories must be used as ® instructed by MKS Instruments, Inc., HPS Division, to ensure safe operation. Use or modification of the equipment in a manner not consistent with specifications may render the product's inherent protection useless.
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Page 11: Specifications
Specifications Controller Measuring Range 1.0 x 10 to 1.0 x 10 Torr to 1.0 x 10 microns 1.3 x 10 to 1.3 x 10 mbar 1.3 x 10 to 1.3 x 10 Useful Set Point Range 2.0 x 10 to 9.9 x 10 Torr to 9.9 x 10 microns... - Page 12 Output Voltage 0.33 to 5.63 VDC, buffered analog, 1 kW maximum output impedance Fuse Rating, Size T 0.16 A, Ø 5 mm x 20 mm for 90 to 130 VAC; T 0.063 A, Ø 5 mm x 20 mm for 210 to 250 VAC Display LED with 2 significant digits (1 leading) and 1 signed exponent;...
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Page 13: Sensor Tube
Sensor Tube Calibration Gas Air/nitrogen Horizontal only Installation Orientation Materials Exposed to Vacuum 304 stainless steel, platinum, glass, nickel Repeatability 5% of indicated pressure @ T const Internal Volume 2.0 in. (33.0 cm ) maximum Operating Temperature Range 0° to 50°C (32° to 122°F) Maximum Bakeout Temperature 200°C (392°F), 100°C (212°F) shielded;... -
Page 14: Feature And Control Locations
Feature and Control Locations Controller Side View Digital LED Display Power On-Off Rocker Switch View Set Point Push-buttons Set Point Adjustment Potentiometers LED Set Point Indicators Atmospheric Adjustment Potentiometer Zero Adjustment Potentiometer Power Cord Inlet w/ Fuse Holder Panel Mounting Fastener Holes Female, 9-pin Gauge Port Male, 9-pin Accessory Port Slots (for Optional Mounting Brackets) -
Page 15: Typical Applications For The Series 947 Cep System
Typical Applications for the Series 947 CEP System Measuring foreline and roughing pressures generated by mechanical vacuum pumps Controlling valves and pumps to automate system pump down using the relay set points Sensing abnormal pressure and taking appropriate security measures using the relay set points Controlling system pressure using the analog output as input to an automatic pressure controller Starting or stopping system processes using the relay set points... -
Page 16: About The Sensavac Series 947 Cep Vacuum Sensor System
® About the SensaVac Series 947 CEP Vacuum Sensor System The Series 947 Convection Enhanced Pirani (CEP) System, together with its Sensor and connecting cable, provides accurate and reliable data for processes which need pressure control from 10 Torr to 10 Torr. -
Page 17: Installing The Series 947 Cep System
Installing the Series 947 CEP System CEP Sensor Installation Location Locate the CEP Sensor where it can measure chamber or manifold pressure. Install it away from pumps and gas sources and where vibration is minimal to give the most representative values. Orientation The CEP Sensor can only be installed horizontally to work effectively in the convection region. -
Page 18: Cep Controller Installation
To fit the Sensor with the /8" NPT, do not use the case for tightening. The Sensor's vacuum tubing has /16" hex flats for tightening. Wrap a layer of Teflon ® tape on the threads of the tubing, in the direction of installation, to ensure a leak-free seal. -
Page 19: Connecting The Sensor To The Controller
Adhesive backed rubber feet for bench top use are provided with the mounting kit. Remove the adhesive backing from each foot and apply one to each corner of the aluminum bottom surface. Connecting the Sensor to the Controller A sensor cable with 9-pin D-sub connectors (see Accessories, p.26) is required for operation but is purchased separately from the CEP System. -
Page 20: Ac Power Cord
In applications for which special cables are required, i.e., where the connection must be routed through restrictive barriers or through a conduit, customize the cable using the figure shown below. For short lengths, any cable wired straight through, e.g., pin 1 to pin 1, will suffice. -
Page 21: Relay Inductive Loads And Arc Suppression
Do not inadvertently short circuit the set point relay terminals to the analog output voltage. Relay Inductive Loads and Arc Suppression If the set point relay is used to switch inductive loads, e.g. solenoids, relays, transformers, etc., the arcing of the relay contacts may interfere with Controller operation or reduce relay contact life. -
Page 22: Operating The Series 947 Cep System
Operating the Series 947 CEP System Reading Pressure The Sensor must be connected to the Controller before turning on the unit. Turn the power on to display pressure or to operate the set point relays. The table below shows the Series 947 CEP System’s voltage output as a function of pressure for nitrogen, argon, and helium, and the graph on the next page gives the same information. - Page 23 At pressures above 1000 Torr, the Series 947 System's upper measuring limit, the Controller display will show When using the graph, remember that the pressure scale is logarithmic, and the voltage scale is linear. Equal increments of distance along the pressure scale do not correspond to equal pressure changes.
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Page 24: Sensor Adjustment
Sensor Adjustment Series 947 CEP Controllers and their Sensors are calibrated at HPS ® However, instances in which user-calibration will be required are: After installation on your system, the Controller and Sensor need to ® be calibrated as a unit. They are not calibrated as a unit at HPS From Sensor to Sensor, readings may differ. -
Page 25: Venting To Atmosphere
open. When an LED is off, the measured pressure is above the set point value, the normally open relay contact is open, and the normally closed contact is closed. Venting to Atmosphere The CEP Sensor senses pressure by measuring heat loss from a heated fine wire. - Page 26 The pressure will either rise or fall, depending upon the thermal conductivity of the probe gas relative to the system gas. The largest change in value indicates the probe gas is nearest the leak location. 4) Repeat the test to confirm. As with any leak testing, many factors can influence the sensitivity of the test.
- Page 27 If the above detection method does not locate a leak, unexpected high pressures may be caused by a virtual leak, i.e., outgassing of a system component. You can locate outgassing parts, or "virtual leaks", as well as true gas leaks, using the rate-of-pressure-rise method. 1) With the Controller on, pump down the system to a base pressure.
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Page 28: Using The Series 947 Cep System With Other Gases
Using the Series 947 CEP System with Other Gases Before using the Series 947 CEP System to measure pressure of gases other than air or nitrogen, you should read and understand this section. To answer further questions, contact ® Applications Engineering at HPS 1-303-449-9861 or 1-800-345-1967. -
Page 29: Calibrating For Other Gases
3. Locate the point at which a vertical line from the He or Ar curve intercepts the pressure axis. This point corresponds to the true pressure for He or Ar. The nitrogen equivalent pressures of some gases can exceed the measuring capabilities of the Series 947 CEP Controller. -
Page 30: Maintaining The Series 947 Cep System
Maintaining the Series 947 CEP System Troubleshooting and Service The Series 947 CEP Controller is designed to be maintenance-free under normal operation. If a problem should occur, the following chart lists symptoms, possible causes, and their remedies. With this guide, you should be able to diagnose some problems and correct them. -
Page 31: Cleaning The Cep Sensor
Cleaning the CEP Sensor Roughing pump oils and other fluids condensing or decomposing on the heated filament can contaminate the Sensor. This changes the emissivity of the filament, which in turn can cause the calibration to change, especially at low pressure. It is not advisable to clean the Sensor. -
Page 32: Preparing For Bakeout
Preparing for Bakeout Remove the cable from the CEP Sensor. As shown on the previous page, use a #1 Phillips head screwdriver to remove the two screws at the end of the connector/electronics subassembly to separate it from the Sensor. The standard CEP Sensor can be baked up to 200°C and the Shielded CEP Sensor can be baked up to 100°C. -
Page 33: Accessories
Accessories Part # Accessory Connector, 9-pin 100004031 Accessory Connector Shell, 9-pin 100005777 Cables for the CEP Sensor 10 ft ( 3.0 m) 103170006 25 ft ( 7.6 m) 103170007 50 ft (15.2 m) 103170008 100 ft (30.5 m) 103170017 Custom Lengths to 500 ft 103170009 CEP Sensors KF 16... - Page 34 Adaptive, Al, Viton ® 100315811 6.90 KF 16 to KF 10 Adaptive, Al, Viton ® 100315813 7.90 KF 25 to KF 20 Adaptive, Al, Buna-N, 100315801 4.50 KF 16 to KF 10 Adaptive, Al, Buna-N, 100315803 5.80 KF 25 to KF 20 SensaVac ®...
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Page 35: Product Warranty
III. This warranty gives PURCHASER specific legal rights, and PURCHASER may also have other rights which vary from state to state. ® IV. For HPS products sold outside of the U.S., contact your MKS representative for warranty information and service. Warranty Performance ®... -
Page 36: Notes
Notes ® Products Series 947 CEP System... -
Page 37: Appendix A: How The Series 947 Cep System Works
Appendix A: How the Series 947 CEP System Works The Series 947 CEP System is a heat-loss manometer which infers the pressure of a gas by measuring thermal loss from a heated wire. Theory of a Thermal Conductivity Sensor A hot wire suspended from supports in a partial vacuum loses thermal energy in three ways: gas transport, which is pressure dependent, end loss to the supports, and... -
Page 38: The Series 947 Cep System Design Overview
The Series 947 CEP System Design Overview This section is intended to give the reader an overview of the internal workings of the Series 947 CEP System. This manual does not provide sufficient detail for advanced levels of troubleshooting. Refer to the block diagram while reading this section.
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