Setra 370 Operating Manual

Operator's Manual

Model 370

Digital Pressure Gauge

Table of Contents

INTRODUCTION

About this Manual....................................................................................... iii

SECTION ONE

Installing the Model 370 ..............................................................................1

SECTION TWO: SUMMARY OF FUNCTIONS

2.1 Keyboard Functions ............................................................................3

2.2 Display Symbol....................................................................................4

2.3 Display Messages ...............................................................................5

SECTION THREE: DIGITAL PRESSUREGAUGE FUNCTIONS

3.1 Entering a Number or Function ...........................................................7

3.2 Clearing a Number or Function ...........................................................7

3.3 If You Make a Mistake.........................................................................7

3.4 Converting Engineering Units..............................................................8

3.5 Tracking Min and Max Values .............................................................8

3.6 Setting and Checking Alarm Setpoints................................................9

3.7 Tares and Offsets..............................................................................10

3.8 Printing Out Information ....................................................................11

3.9 Repetitive Printing .............................................................................12

3.10 Printing Setup Status.........................................................................13

3.11 Interfacing with a Computer ..............................................................13

SECTION FOUR: ADVANCED PRESSUREGAUGE FUNCTIONS.

4.1 User Defined Engineering Units ........................................................15

4.2 Digital Altimeter Setting Indicator (DASI) ..........................................17

SECTION FIVE: DISPLAYING ALTITUDE

5.1 Standard Altitude Conversions..........................................................19

5.2 True Corrected Altitude .....................................................................20

5.3 Relative Altitude ................................................................................22

Appendices

Appendix I: SETUP FUNCTIONS

I.1 Formatting Baud Rate .......................................................................23

I.2 Disabling Beeper...............................................................................24

I.3 Programmable Stability Indicator ......................................................24

I.4 Omitting Engineering Units................................................................25

I.5 Software Revision Number................................................................25

I.6 Self Diagnostics.................................................................................26

Appendix II: CALIBRATION

II.1 Zero Calibration.................................................................................27

II.2 Span Calibration................................................................................28

Appendix III: RS-232 SERIAL DATA COMMUNICATIONS

III.1 Interfacing Setra 370 to a Computer .................................................29

III.2 Sending Commands to the 370.........................................................30

III.3 Receiving Data from the 370.............................................................31

III.4 Immediate and Repetitive Print Modes .............................................32

III.5 Verify Function ..................................................................................32

III.6 Status After Power is Applied............................................................32

III.7 RS-232 Interface Hardware...............................................................33

Appendix IV: ACCESSORIES AND OPTIONS

IV.1 Battery Powered Operation ...............................................................35

IV.2 In Case of Difficulty ...........................................................................36

IV.3 Options ..............................................................................................36

IV.4 Specifications ....................................................................................37

Appendix V: WARRANTY INFORMATION

V.1 Limited Warranty - Pressure Products ..............................................39

Introduction

Congratulations, and thank you for purchasing a SETRA Model 370 high accuracy Digital PressureGauge. Its ease of operation and durable construction will provide years of reliable service. While thegauge is easy to operate, it is advisable to read this guide carefully before use. It is designed to help you take full advantage of the functions and performance of the gauge.

This guide is divided into five major sections: Section One explains installation and power requirements for the Model 370. Section Two provides a summary of the various keys, functions, displays and

messages you will encounter when using this pressure gauge. Section Three explains in detail the basic functions and uses of this gauge in

pressure measurement. Section Four describes some advanced pressure measurement features avail-

able in the Model 370. Section Five provides detailed instructions for the correct measurement of

altitude for Model 370's with absolute or barometric pressure sensors. The Appendices include calibration and setup information, and instructions for

interfacing the gauge with computers and other equipment. Also provided are specifications, lists of accessories, and a warranty statement.

iii

OUTLINE DRAWING

Side View

5.5

140

8.55 217

Rear View

AC Power

Pressure Port

RS-232 I/O

6.0

152

7.2

183

7.5

191

8.55 217

On/Off

(Battery Only)

Section One

INSTALLING THE MODEL 370

The Setra Digital PressureGauge, Model 370, is a highly accurate pressure measurement system utilizing the patented SETRACERAM sensor, advanced microcomputer based electronics, and sophisticated firmware, resulting in a 0.02% FS system accuracy.

The unusual ergonomic design of the Model 370 allows it to be used as a bench top instrument (with keypad and display at the proper angle for viewing), as a portable device with a built in carry handle, or as a rack mount instrument with the optional 19" rack mount kit.

SETUP

Connect the pressure gauge to an AC outlet by inserting one end of the provided power cord into the back of the gauge, and the other end of the cord to the AC outlet. The gauge will operate at any voltage from 100 to 240 VAC, 50 or 60 Hz. Once you have plugged your gauge into a live outlet, it is automatically on.

The gauge uses very little power, and may be left connected permanently. If you have the optional battery, refer to Appendix IV concerning battery power and

automatic recharging.

DISPLAY TEST

When your gauge is first powered on, it automatically performs a display test, showing all possible display segments. This test lasts approximately six seconds. The gauge next displays "HELLO" and performs self-diagnostics to ensure proper operation. The gauge then counts down to zero, and is ready for use.

PRESSURE CONNECTIONS

The Model 370 provides a standard 1/8" NPT female pipe thread pressure port with filter, for connection to a variety of available fittings. The pressure gauge is rated for clean dry gas (nonconductive/noncorrosive).

The Proof Pressure of the Model 370 (the maximum pressure which can be applied without disturbing the calibration of the gauge) is 150% of the full scale pressure. To ensure that the pressure applied to the gauge does not exceed the proof pressure, properly rated relief valves should be installed in any system this gauge is connected to.

That's all there is to installation. It is important that you read this User's Guide thoroughly to ensure proper use of the gauge. The summary of Functions in the next Section serves as a handy reference.

Portability and Accuracy Right Where You Need It

6 digit LCD with Annunciators for

Display

Alarms, Min/Max values and

Engineering Units.

O.K.

User Program-

mable Indication

of Pressure Signal

Stability.

Keypad

Numeric keypad for

Entry of Custom

Conversion Factors,

Setpoints and

Calibration Data.

Digital Pressure Gage

SEA

LEVEL

-888888

O.K.

HI LO ALARM

7 8 9 4 5 6 1 2 3

Tracks Minimum and Maximum

units ft mmbar

in hg

H2O PSI

f(p)

clear

set

points

min

max

set up zero

print span

conv

min/max

Values Encountered.

f(p)

Programmable Non-

Linear Function Key for

Barometric Ranges.

Converts True Baromet-

ric Pressure To Sea

Level Pressure.

set points

Hi/Lo Alarms-User Defined.

Alarm Indications are

Display Flashing, Audible

Tone and Message Sent

Out I/O Port.

zero

Dual Function Key

Operates as Tare or

with SetUp key as

Zero Calibration.

span

Use with SetUp

Key for Full Scale

Calibration.

set up

Program Custom

Functions and

Perform

Recalibration.

Sends Display Data Through a Bidirectional RS-232 I/O Port. Programmable for Continous or Interval Printing,

300-9600 Baud Rate.

Exits Programming Mode To

clear

Normal Operation.

conv

Automatic Engineering Units

Conversion for Pressure and Altitude. Predefined Units are hPa, PSI, mbar, mmHg, inHg,

mmH2O, inH2O, ft, m, units.

2.1 KEYBOARD FUNCTIONS

Section Two

SUMMARY OF FUNCTIONS

setup

conv

set

points

zero

min

max

clear

f(p)

Send information to a printer or other peripheral.

Convert engineering units being displayed.

Display HI and Lo Alarm setpoints.

Enter relative or absolute tare value.

Display minimum and maximum value encountered.

Clear the number or key sequence being entered or displayed.

Convert true pressure to SEA-LEVEL pressure (absolute pressure).

Send status summary to a printer or other peripheral.

setup

set

points

min

max

min

max

zero

span

clear

Change Hi and Lo Alarm setpoints.

Enter MIN/MAX tracking mode.

Exit MIN/MAX tracking mode.

Perform ZERO calibration procedure.

Perform SPAN calibration procedure.

Clear the display, turn off MIN/MAX, clear the tare value, convert to display the units the gauge was calibrated in.

2.2 DISPLAY SYMBOLS

hPa

PSI

inHg

mbar

mmHg

inH2O

mmH2O

SEALEVEL

units

HI ALARM

The readings are within the user defined stability requirement. The reading shown is given in hectopascals. The reading shown is given in pounds per square inch. The reading shown is given in inches of mercury. The reading shown is given in millibars. The reading shown is given in millimeters of mercury. The reading shown is given in inches of water. The reading shown is given in millimeters of water. The reading shown is given in feet of altitude. The reading shown is given in meters of altitude. The reading shown is corrected to sea level. The reading shown is given in user-defined pressure units. The reading shown exceeds the HI setpoint.

LO ALARM

The reading shown exceeds the LO setpoint. The reading shown is the maximum value encountered. The reading shown is the minimum value encountered.

2.3 DISPLAY MESSAGES

UnAbLE

The gauge is unable to execute the requested function in its current configuration. Clear the display and continue.

OFLO

The display is over-ranged because excess pressure is applied or because the user-defined conversion exceeds the number of digits available in the display.

FLASHING DISPLAY

BUSY

The pressure applied exceeds the rated range of the sensor.

The gauge is acquiring a stable reading.

Other messages which are displayed in the course of using the various functions of the Model 370 are explained in the sections of the manual concerning those functions.

Section Three

DIGITAL PRESSURE GAUGE FUNCTIONS

3.1 ENTERING A NUMBER OR FUNCTION

To enter a number or function, simply press the key or keys which correspond to the numbers or functions you wish to enter.

3.2 CLEARING A NUMBER OR FUNCTION

To clear a function or number you have begun to enter, press the CLEAR key. This automatically returns the gauge to display mode, without affecting any other functions which may be in use.

To reset the Model 370 to its power up condition, press "-", then CLEAR. This clears the zero/tare value, shuts off MIN/MAX, and converts back to the original engineering units. All of these functions are described in later sections of this guide.

3.3 IF YOU MAKE A MISTAKE

If you mis-enter a number or enter a number or function the gauge cannot accept, the display will read "UnAbLE". Press CLEAR to resume normal display, and re-enter the number or function.

3.4 CONVERTING ENGINEERING UNITS

The Model 370 will measure pressure in any engineering units, including six built-in pressure conversions, two built-in altitude conversions, and a user definable conversion.

To convert from one unit to another, simply press the CONV key repeatedly until the units you want are in the display. The order of units is as follows: hPa - PSI - mbar - mmHg - inHg - mmH2O - inH2O - ft - m - units. To return directly to the units the gauge was calibrated in, press "-" then CONV.

See Section 4.1 for instructions on the use of user-defined units ("units"), or Section 5 for displaying altitude.

3.5 TRACKING MIN AND MAX VALUES

To use the Model 370 to track the minimum and maximum pressures applied to the sensor, enter the tracking mode by pressing SETUP, then MIN/MAX.

To examine the values stored, press MIN/MAX. The gauge will display "HI" and the maximum value encountered for about three seconds, then will display "LO" and the minimum value encountered for about three seconds, and then will revert to normal display.

To shut off the min/max tracking mode, press "-", then MIN/MAX. If the MIN/MAX key is pressed without having first entered the MIN/MAX

tracking mode as described above, the display will read "UnAbLE". Press CLEAR and then follow the above procedure.

3.6 SETTING AND USING ALARM SETPOINTS

The Model 370 has an alarm capability which will indicate when the pressure applied has exceeded a high or a low setpoint. The annunciators are an audible tone, a display message of "HI ALARM", and a message sent through the communications port.

To examine the current value of the setpoints, press SETPOINTS. The gauge will display "HI ALARM" and the high setpoint for about three seconds, then will display "LO ALARM" and the low setpoint for about three seconds, and then will revert to normal display.

To enter new setpoints, convert to the engineering units you wish to use, and decide what values you will enter in the following procedure. Entering a value which is too high or too low will cause the display to read "UnAbLE". If this happens, press CLEAR to resume normal display mode.

1. Press SETUP, then SETPOINTS. The display will show "HI ALARM" and the current high setpoint.

2. Now you can enter a new high setpoint by entering a number. To keep the current setpoint without changing it, proceed to the next step without entering a new number.

3. Press SETUP. The Model 370 will accept the number in the display as the high setpoint, and immediately show "LO ALARM" and the low setpoint.

4. Enter a new low setpoint, or to keep the current low setpoint, proceed to the next step without entering a number.

5. Press SETUP. The number in the display will be accepted as the low setpoint, and the gauge will revert to its normal display.

The factory setting for the high setpoint is 105% of the pressure range, and the low setpoint is 5% below the pressure range. To effectively disable the alarm setpoints, reset them to these values using the above procedure for entering setpoints.

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