MKS HPS 917 User manual

HPSTM Products Series 917
PiraniVacuum Sensor System
OPERATION AND
MAINTENANCE MANUAL

Pirani Vacuum Sensor System
HPS™ Products Series 917
PiraniVacuum Sensor System
AUGUST 1999
PART #109170020 REV.B

Pirani Vacuum Sensor System
Part#1091700XX
– __ __
Serial # __ __ __ __ __ __
Please fill in these numbers and have
themreadily availablewhen callingfor
serviceoradditionalinformation.
(The part number can be found on your
packing slip, and the serial number is
located on the back panel of the Pirani
controller.)
© 1994, 1996 by MKS Instruments Inc., HPSTM Products Inc. All rights reserved.
SensaVacisatrademarkofMKSInstruments,Inc.
TeflonisaregisteredtrademarkofDuPontCo.
VCR®isaregisteredtrademarkofSwagelok®Company.
Formoreinformation orliterature,contact:
MKS Instruments Inc., HPSTM Products, Inc.
5330SterlingDrive
Boulder,CO80301USA
Phone: [phone]
800-345-1967
FAX: [phone]

Pirani Vacuum Sensor System
Table of Contents
Table of Contents
Package Contents ..................................................................... 1
Symbols Used in this Manual.................................................... 1
Safety Precautions and Other Procedures ................................ 2
Specifications............................................................................ 4
Controller................................................................................................. 4
SensorTube ............................................................................................ 5
Feature and Control Locations .................................................. 6
Typical Applications for the Series 917 Pirani System .............. 7
About the HPS™ Series 917 Pirani Vacuum Sensor System.... 8
Installing the Series 917 Pirani System..................................... 9
Pirani Sensor Installation ........................................................................ 9
Location............................................................................................................................ 9
Orientation........................................................................................................................ 9
Contamination .................................................................................................................. 9
Venting to Atmosphere.................................................................................................... 9
Vacuum Connection ........................................................................................................ 9
PiraniControllerInstallation....................................................................10
Controller Mounting ....................................................................................................... 10
Electrical Connection of the Pirani Sensor to the Controller ...................................... 10
AC Power Cord.............................................................................................................. 11
Fuse Replacement ........................................................................................................ 12
Accessory Connector................................................................................................... 12
Relay Inductive Loads and Arc Suppression .............................................................. 13
Operating the Series 917 Pirani System.................................. 14
Reading Pressure ...................................................................................14
Adjusting the Set Points ................................................................................................ 15
Buffered Analog Output................................................................................................. 16
Use with Computers...................................................................................................... 16
Leak Detection............................................................................................................... 16
Using the Series 917 Pirani System with Other Gases............ 18
CalibratingforOther Gases ....................................................................18
CalibratingforDirect Measurement ........................................................18
Maintaining the Series 917 Pirani System............................... 19
TroubleshootingandService...................................................................19
CleaningtheSeries917Pirani ControllerFront Panel.............................19
Testing the Pirani Sensor ............................................................................................. 20
Cleaning the Pirani Sensor ........................................................................................... 20
Accessories............................................................................. 21
ProductWarranty ..................................................................... 22
Notes....................................................................................... 23

Pirani Vacuum Sensor System

1Pirani Vacuum Sensor System
Please be sure that your Series 917 Pirani Vacuum Sensor System package
contains these items:
1 Series 917 Pirani Controller
1female,15-pin,subminiatureD(D-sub)accessoryconnector
1 power cord
1 HPS™ Series 917 Pirani Vacuum Sensor System
User'sManual
The Series 917 System's Pirani Sensor and its connecting cable are sold
separately.Pleaserefer to page21for necessaryorderinginformation.
If any items are missing from the package, call HPSTM Customer
Serviceat1-303-449-9861or1-800-345-1967.
If the unit has been damaged in shipping, notify the carrier immediately. Keep
all shipping materials and packaging for claim verification.
Package Contents
The first two symbols below, located on your Series 917 Controller and/or
Sensor, identify critical safety concerns. They are used throughout this
manual to further define the safety concerns associated with the part.
The last two symbols identify other information in this manual that is
essential to highlight or useful in achieving optimal performance from the part.
CAUTION: Risk of electrical shock.
CAUTION: Refertomanual.
Failure to heed message could result in personal injury and/or
seriousdamage tothe equipment.
Failure to heed message could result in damage to the
equipment.
Informationcallingattentiontoimportantprocedures,
practices, or conditions.
Symbols Used in this Manual

2Pirani Vacuum Sensor System
Do not use te Serie 917 System's Pirani Sensor with
explosive gas mixtures or with gases that are
combustible in air.
If the control circuit fails or an exothermic catalytic reaction occurs at the
sensor wire, the wire could ignite the gas mixture.
Prevent chances of explosion when using with gases other
than air or nitrogen.
The sensor is calibrated for air/nitrogen, so the measured pressure will differ
fromthetrue pressure of anothergas.Calibrations diverge widelyathigher
pressures. With no linear relationship for the gases, a gas correction factor
couldleadtohazardousoverpressure.Capacitancemanometersand
mechanical dial gauges are best suited for higher pressures. Refer to page 18
for use with other gases.
Takeprecautionstoavoidoverpressureduring
systembackfill.
When backfilling, do not use the Series 917 Pirani System to read pressures
above 100 Torr. In a system which is filled with a pressurized source, install a
safety relief valve or burst disc to safely limit pressure and prevent an
explosion.
The Series 917 Pirani Controller contains lethal voltages
within the casing.
Avoid the danger of electrical shock. Disconnect the power cord before
openingtheControllercase.
Turn off power to the Controller before plugging or
unplugging cables to the Sensor.
TheControlleris groundedthroughthe conductorofthe powercord.Plug the
cord only into a properly grounded outlet. If the protective ground connection
is lost, all accessible conductive parts may pose a risk of electrical shock.
Prevent personnel injury by making sure that only qualified
techniciansservice theSeries 917Pirani System.
Safety Precautions and
Other Procedures

3Pirani Vacuum Sensor System
Nooperations personnelshould removecovers, casings,or plug-in
components. Any part replacement or internal adjustments must be
performed by a qualified technician only.
To prevent damage to the Series 917 Pirani Controller, use
the correctlinevoltage.
The Controller must be used with only the specified line voltage. Use only a
fuse of the correct type, voltage, and current rating. Only qualified personnel
should change line voltage or fuse ratings if required.
Outside of the U.S., use only a harmonized, detachable cord set that has
conductors with a cross-sectional area equal to or greater than 0.75 mm2.
Power cables should be approved by a European agency such as VDE,
Semko, or SEV.
The Series 917 Pirani System and all its accessories must be
used as instructed by MKS Instruments, HPS
TM
Products, to
ensure safe operation. Use or modification of the equipment
in a manner notconsistentwith specificationsmayrender
theproduct'sinherentprotectionuseless.

4Pirani Vacuum Sensor System
Specifications
Controller
MeasuringRange 1.0 x 10-3 to 7.6 x 10+2 Torr
1.0 to 7.6 x 10+5 mTorr
1.0 x 10-3 to 1.0 x 10+3 mbar
1.0 x 10-1 to 1.0 x 10+5 Pa
UsefulSetPointRange 5.0 x 10-3 to 1.0 x 10+2 Torr
5.0 to 1.0 x 10+5 mTorr
6.5 x 10-3 to 1.3 x 10+2 mbar
6.5 x 10-1 to 1.3 x 10+4 Pa
OperatingTemperatureRange 0oto 50oC (32oto 122oF)
StorageTemperatureRange -10oto55oC(14oto131oF)
OperatingHumidity 95%maximum(noncondensing)
InstallationCategory OvervoltageCategoryII,
PollutionDegree2
NumberofChannels 1
FrontPanelControls 2nonvolatile,independentrelayset
points; power on-off switch
RelayContactRating SPDT, 2 A @ 50 VAC resistive
2 A @ 30 VDC
RelayResponse 150 msec maximum
PowerRequirement 90 to 130 VAC, 50/60 Hz
or
210 to 250 VAC, 50/60 Hz
PowerConsumption 7 W
Output Voltage 0.03to3.25VDCbuffered analog,
1 kWmaximum impedance
Fuse Rating, Size T 0.1 A, Ø 5 mm x 20 mm
for 90 to 130 VAC,
T 0.04 A, Ø 5 mm x 20 mm
for 210 to 250 VAC

5Pirani Vacuum Sensor System
Display 3½" wide face, 95odeflection
analog meter; LED set point
indicators; units shown in either
Torr, mbar, Pascal, or
mTorr/microns
ElectronicCasing Aluminum,anodized
Dimensions 3¾" x 7" x 3¾"
(W x D x H) (96 mm x 178 mm x 96 mm)
Size ¼DIN
Weight 2.4 lb (1.1 kg)
Sensor Tube
CalibrationGas Air/nitrogen
InstallationOrientation Any
MaterialsExposed toVacuum 304 stainless steel, platinum,
aluminaceramic,silver brazing
alloy, nickel 200
Internal Volume 0.5 in.3(8.0 cm3) maximum
OperatingTemperatureRange 0oto50oC(32oto122oF)
MaximumBakeoutTemperature 50oC(122oF)
Length 4.4 in. (112 mm)
Diameter 1.3 in. (34 mm)
Typical Weight (with KF Flange) 0.5 lb (0.2 kg)
Fittings/Interface KF 16
8VCR®-F(½")
1/8"NPT-M
with ½" compression seal option
11/3"CF(non-rotatable)
2¾"CF(non-rotatable)
Ø 15.0 mm x 30.0 mm tubing
Ø 18.0 mm x 30.0 mm tubing
Designand/orspecificationssubject to changewithoutnotice.

6Pirani Vacuum Sensor System
AnalogDisplay
PowerOn-OffRocker Switch
View Set Point Push-buttons
Set Point Adjustment Potentiometers
LED Set Point Indicators
PowerCord Inletw/FuseHolder
PanelMountingFastenerHoles
Male, 15-pin Accessory Port
Female,15-pin Gauge Port
Slots (for Optional Mounting Brackets)
Male Octal Socket
SensorVacuumPort
Rear View
Front View
Division
Side View
Controller
Sensor
Feature and Control Locations
1
2
3
4
5
6
7
8
9
10
11
12 12
1
2
34
5
6
7
8
9
11
10

7Pirani Vacuum Sensor System
Typical Applications for the
Series 917 Pirani System
Measuringforelineandroughing pressures generatedby
mechanicalvacuumpumps
Controlling valves and pumps to automate system pumpdown
using the relay set points
Sensingabnormal pressure andtakingappropriatesecurity
measures using the relay set points
Controlling system pressure using the analog output as input to
anautomaticpressurecontroller
Starting or stopping system processes usingtherelay set
points
Measuring pressures of backfilled gases in the range of 10-3 to
10+2Torr
Activatinghigh vacuumgauges intheiroperatingrange

8Pirani Vacuum Sensor System
About the HPS™ Series 917 Pirani
Vacuum Sensor System
The Series 917 Pirani System, together with its Sensor and connecting cable,
providesaccurateand reliabledata forprocesseswhich needpressure control
from atmosphere to 10-3 Torr at a very low cost.
The Pirani Sensor is available with several standard fittings for vacuum
connection. The Sensor connects to the Controller with a cable that has a
standard female octal socket on one end and a male, 15-pin D-sub connector
on the other. The Controller easily mounts into a ¼ DIN panel hole or stands
alone. All controls, even the power switch, are conveniently accessed from
the front panel, and cable connections are
hidden to the rear. The Series 917 Pirani
Controller is compatible with any HPSTM
standard Pirani Sensor without loss of
calibrationaccuracy.
TheSeries 917Pirani
Controllerisuseful
either as a small
system controller or as
amodulein more
sophisticatedpressure
controlenvironments.
TheControllerfeatures
twostandardrelayset
points for process
applications.
Pressure is read from a
highlyvisibleanalog
meter,whileLEDs
indicate the status of
relay set points. Set
pointsareadjusted
independentlyusing
boththepush-
buttonsandpotentiometers
on the front panel.
Theanalog outputandrelay
contacts are accessible from the
Accessory port on the rear panel.
The Sensor can be located away from
the Controller using an optional cable as long as 500 feet in length.

9Pirani Vacuum Sensor System
Installing the
Series 917 Pirani System
Pirani Sensor Installation
Location
LocatethePirani Sensor where itcanmeasure chamber ormanifoldpressure.
Installing the Sensor away from pumps and gas sources gives the most
representative values. Place the Sensor where vibration is minimal.
Orientation
Operating position has no negative effect on accuracy. The Pirani Sensor
was designed to minimize convection. In a standard Pirani system, the
pressure reading of a horizontal versus a vertical sensor at atmospheric
pressure differs negligibly from the residual convection effect.
The Sensor is factory calibrated vertically with the vacuum port facing down.
Contamination
Locate and orient the Pirani Sensor to avoid contamination which might affect
the tube's element. For example, if the Sensor is installed directly above a
roughing pump in the system, oil vapor could contaminate the tube's filament
wire and cause the emissivity and the calibration to shift.
Install the Sensor with the vacuum port facing downward whenever possible
to prevent particulates and liquids falling or flowing into it. Using a screen or
porous filter at the port is helpful. Try an HPSTM seal and centering ring
assembly with a screen (see Accessories, p. 21).
VentingtoAtmosphere
The Pirani Sensor senses pressure by measuring heat loss from a fine
heated wire. Sudden venting at its port can greatly stress the Sensor
physically.
To avoid damage to the Sensor, vent the vacuum system to
atmospherebeforeremovingit.
VacuumConnection
Standard vacuum interfaces for the Pirani Sensor include:
KF 16 flange 8 VCR®-F (½") fitting
11/3"CFflange Ø 15 mm x 30 mm tubing
2¾" CF flange Ø 18 mm x 30 mm tubing
1/8" NPT-M fitting with a ½" compression seal

10 Pirani Vacuum Sensor System
To fit the KF 16 port to a KF 10 port, use an HPSTM adaptive centering ring
(seeAccessories,p.21).
To fit the Sensor with the 1/8" NPT, do not use the case for tightening. The
Sensor’s vacuum tubing has 9/16" hex flats for tightening. Wrap some Teflon®
tape on the threads of the Sensor, in the direction of installation, to ensure a
leak-freeseal.
Instead of the NPT fitting, you may opt to use the ½" O-ring compression
seal against the vacuum tubing above the thread, but the O-ring seal cannot
be used for positive pressure applications .
A solid electrical connection between the Sensor and the
grounded vacuum system must be provided to shield the
tubeelement fromexternal radiationsources. Inapplications
where the system may be exposed to large voltage
fluctuations, a centering ring with a screen should be
installed, and the screen and tubing then grounded.
Pirani Controller Installation
ControllerMounting
TheSeries917PiraniControllerisdesignedforeitherpanelmounting orfor
stand-aloneuse.Regardlessofthemethodyouchoose,assure adequate
ventilation to the Controller with at least a ½ inch left open above and below it.
Adhesive backed rubber feet are provided for bench top use. Remove the
adhesive backing from each foot and apply them to each corner of the
aluminumbottomsurface.
An optional hardware kit is also available for mounting the Controller into a
standard ¼ DIN cutout in a panel up to 3/16-inch thick (see Accessories,
p. 21). A dimensioned illustration shows the required cutout on the top of the
next page. Leave at least 3 inches of clearance behind the Controller's rear
panel to accommodate the connectors and cables.
Mount the Controller into the panel by slipping it through the cutout from the
front. Slide the panel mounting brackets into the slots on either side of the
Controllerfromthe rear, andsecurethem with thethumbscrewsprovided.
Electrical Connection of the Pirani Sensor to the Controller
Connect the Pirani Sensor to the Controller with a sensor cable (see
Accessories, p. 21). This cable has a standard octal socket. With an
integrated polarizing tab, the socket has sufficient contact pressure so that
strain relief is unnecessary in most applications.

11Pirani Vacuum Sensor System
Panel mounting system with a ¼ DIN cutout
Turnoff theControllerbeforeconnecting ordisconnecting
the cable from the Sensor or Controller. Pin 6 of the octal
socketis intentionallyshorter asasafety measuretoprevent
a voltage overload on the Sensor in case the Controller has
not been shut off. However, it is not possible for this
preventativefeature toalwayswork, soavoid anypossible
damagebyalwaysturning off theController beforeany
connectionsaremade.
When excessive stress on the cable must be exerted, use separate
strain relief to avoid damage to the Sensor or Controller. The cables
are available in standard lengths of 10, 25, 50, and 100 feet, and in
custom lengths up to 500 feet.
Connect the cable to the rear of the Controller at the D-sub port labeled
Gauge . Tighten the connector jackscrews into the mating screwlocks to
ensure proper electrical connection and to prevent stress on the connectors.
In applications for which special cables are required, i.e., where the
connectionmustbe routed throughrestrictivebarriers or throughaconduit,
wire the cable using the figure shown on the following page. A D-sub
connector with jackscrews for strain relief should be used in all applications.
ACPower Cord
The Series 917 Pirani System includes a standard, 120 VAC, 50/60 Hz
power cord with a female IEC-320 connector. If a power source or
connection is different, use a harmonized, detachable cord set with
conductors with a cross-sectional area equal to or greater than 0.75 mm2.
The power cable should be approved by a qualified European agency such
as VDE, Semko, or SEV.

12 Pirani Vacuum Sensor System
FuseReplacement
TheSeries917 PiraniControllerhas acombinedfuse holderandIEC-320 port
located on the rear panel. Replace the fuse following the steps below.
1. Unplug the power cord from the IEC port.
2. Use a small screwdriver to pull open the fuse holder.
3. Replace the fuse with one of the following time-lag fuses:
T 0.1 A (Ø 5 mm x 20 mm) – 90 to 130 VAC
T 0.04 A (Ø 5 mm x 20 mm) – 210 to 250 VAC.
4. Close and secure the fuse holder.
AccessoryConnector
Relay set point contacts and the analog output voltage can also be accessed
from the D-sub port, labeled Accessory , on the rear panel of the Pirani
Controller. A connector kit is provided with the Pirani System. The figure and
chart on the next page identify the pin functions of the Accessory port.
Donot inadvertentlyshortcircuit theset pointrelay contacts
to the analog output voltage.
Customizing a sensor cable
Tube Controller

13Pirani Vacuum Sensor System
Pin Description
1 Set point relay 1 - normally closed contact
2 Set point relay 1 - common
3 Set point relay 1 - normally open contact
4 Set point relay 2 - normally closed contact
5 Set point relay 2 - common
6 Set point relay 2 - normally open contact
7 Notused
8 Notused
9 Notused
10 Notused
11 Analogoutputvoltage (+)
12 Analogoutputvoltage(-)
13 Notused
14 Notused
15 Notused
RelayInductiveLoadsandArcSuppression
If a set point relay is used to switch inductive loads, e.g. solenoids, relays,
transformers, etc., the arcing of the relay contacts may interfere with
Controlleroperationor reduce relaycontactlife. An arcsuppressionnetwork,
shown schematically to the left, is recommended. Values of the capacitance
C and the resistance R can be calculated by the equations,
C = I
2/(1 x 107) and
R = E/I
a
where,
C is in farads
R is in ohms
I is DC or ACpeak load current in amperes
E is DC or ACpeak source voltage in volts
a = 1 + (50/ E ).
R
min
= 0.5 W and C
min
= 1.0 x 10-9 F.
15-pin Accessory port
E
C
R
Relay contact
Load
Relay arc suppression network
Note that,

14 Pirani Vacuum Sensor System
Operating the
Series 917 Pirani System
Reading Pressure
TheSensormust be connectedtothe Controller beforeturning
on the unit.
Turn the power on to display pressure or to operate the set point relays. The
graph below shows the Series 917 Pirani System’s voltage output as a
function of pressure for nitrogen, helium, and argon and the table on the next
page gives the same information.
Pressure
(Torr)
3
2
1
0
Output Voltage
(VDC)
He
N2
Ar
10-3 10-2 10-1 10010+1 10+2 10+3