MKS Baratron 631D, Instruction Manual, Page: 26 / 64

Chapter One: General Information
18
overpressure conditions (45 psia). The high overpressure limit, coupled with the high temperature
operation, ensures maximum zero stability. The 631D transducer diaphragm design results in
extremely low hysteresis and the ability to specify a

0.50% accuracy as a percentage of Reading
instead of as a percentage of Full Scale. Since the accuracy is based on a percentage of Reading,
the transducer can be used over a wide dynamic measuring range without the need for re-ranging,
thus it provides accurate process monitoring over a variety of operating conditions.
This product can be used for pressure and vacuum measurements with a wide variety of process
gases, including (but not limited to) toxic, pyrophoric, and oxidizing materials such as silane
(SiH
4
), dichlorosilane (Cl
2
H
2
Si), trichlorosilane (Cl
3
HSi), anhydrous ammonia (NH
3
), ozone (O
3
),
and de-ionized water vapor (DIW). However, it is not recommended for use with corrosive or
explosive gases, so please contact the MKS Applications group or your local MKS Account
Manager if you plan to use the product with such gases.
This product contains electronic components made with non-toxic metals, and the packaging
materials are recyclable plastics. However, at the end of life of the product, decommissioning
must be performed in accordance with your local environmental regulations in consideration of
the chemicals and gases that this product has been exposed to.
How This Manual is Organized
This manual is designed to provide instructions on how to set up, install, and operate a Type
631D unit.
Before installing your Type 631D unit in a system and/or operating it, carefully read and
familiarize yourself with all precautionary notes in the
Safety Messages and Procedures
section at the front of this manual. In addition, observe and obey all
WARNING
and
CAUTION
notes provided throughout the manual.
Chapter One, General Information , (this chapter) introduces the product and describes the
organization of the manual.
Chapter Two, Installation , explains the environmental requirements and describes how to mount
the instrument in your system.
Chapter Three, Overview , gives a brief description of the instrument and its functionality.
Chapter Four, Operation, describes how to use the 631D unit and explains all the functions and
features.
Chapter Five, Optional Trip Point Relay System , discusses the optional relay system and its
parameters, including measuring and adjusting the trip point values and specifying the trip point
direction.
Chapter Six, Maintenance and Troubleshooting , provides a few maintenance recommendations
and a brief troubleshooting section. The Type 631D transducer is highly reliable and requires
little maintenance.
Appendix A, Product Specifications , lists the specifications of the instrument.
Appendix B, Model Code Explanation, describes the model code.