Sierra 730 User Manual

Sierra Series 730 Accu-Mass

Mass Flow Meters

Instruction Manual

Part Number IM-73-AM

Revision E 05/04

™

5 Harris Court, Building L Monterey, CA 93940

[phone] [phone] Fax [phone]

http://www.sierrainstruments.com

Sierra Instruments b.v. Bolstoen 30A 1046 AV Amsterdam The Netherlands

[phone] Fax [phone]

Customer Notice

Sierra Instruments, Inc. is not liable for any damage or personal injury, whatsoever,
resulting from the use of Sierra Instruments standard mass flow meters for oxygen
gas. You are responsible for determining if this mass flow meter is appropriate for
your oxygen application. You are responsible for cleaning the mass flow meter to
the degree required for your oxygen flow application.

© COPYRIGHT SIERRA INSTRUMENTS 1994
No part of this publication may be copied or distributed, transmitted, transcribed, stored in
a retrieval system, or translated into any human or computer language, in any form or by
any means, electronic, mechanical, manual, or otherwise, or disclosed to third parties
without the express written permission of Sierra Instruments. The information contained in
this manual is subject to change without notice.

TRADEMARKS
Accu-Mass™ is a trademark of Sierra Instruments, Inc. Other product and company
names listed in this manual are trademarks or trade names of their respective manufac­turers.

Revision D: added NEMA 4 enclosure wiring instructions, updated content and format.

Series 730 Instruction Manual

Table of Contents

Series 730 Mass Flow Meters...........................................................3

Safety Information..........................................................................4

Receipt of Components...................................................................4

Technical Assistance.......................................................................4

Installation Overview......................................................................5

Unobstructed Flow Requirements...............................................5

Installation......................................................................................6

Wiring Connections - NEMA 2 Enclosures......................................7

Wiring Connections - NEMA 4 Enclosures......................................7

Output Signal Wiring.......................................................................8

Troubleshooting the Flow Meter......................................................8

Returning Equipment to the Factory..............................................10

Product Specifications...................................................................11

Figures

1. Series 730 Sensor Assembly......................................................3

2. Recommended Pipe Length Requirements................................6

3. NEMA 2 Wiring Connections..................................................7

4. NEMA 4 Wiring Connections..................................................7

IM-73-E 1

Warnings and Cautions

Warning! All wiring procedures must be performed with the power Off.

Caution! All flow meter connections and fittings must have the same or higher pres-

sure rating as the main pipeline.

Caution! Do not connect power to the 4-20 mA terminals.
Caution! Before attempting any flow meter repair, verify that the line is de-pressurized.
Caution!

Always remove main power before disassembling any part of the flow meter.
Caution! Printed circuit boards are sensitive to electrostatic discharge. To avoid dam-

aging the board, follow these precautions to minimize the risk of damage:

Series 730 Instruction Manual

• before handling the assembly, discharge your body by touching a grounded,
metal object

• handle all cards by their edges unless otherwise required

• when possible, use grounded electrostatic discharge wrist straps when handling

sensitive components

2 IM-73-E

Series 730 Instruction Manual

Series 730 Mass Flow Meters

Sierra’s Series 730 Accu-Mass™ Flow Meters provide outstanding
measurement accuracy and fast 200 millisecond response time. The
meters monitor the mass flow rate of air and process gases in ranges
from 0 to 250 scfm. They are available in pipe sizes from 1/4-inch to
3 inches. Accu-mass meters are ideal for monitoring flows of non­corrosive gases compatible with the device’s wetted materials and ap­plications requiring fast time response.

Sierra’s Accu-Mass sensor is a reference-grade platinum resistance
temperature detector (RTD) encapsulated in glass. The platinum RTD
wire is wound on a rugged ceramic mandrel for strength and stability.
The sensor is located at the tip of a 304 stainless steel probe which is
inserted in the gas stream. The sensor consists of two sensing ele­ments–a velocity sensor and a temperature sensor which automati­cally corrects for changes in gas temperature. When power is applied
to the flow meter, the transducer electronics heats the velocity sensor
to a constant temperature differential above the gas temperature. The
cooling effect of the air as it passes over the heated sensor is meas­ured by the bridge voltage. The meter electronics converts this volt­age into a linear 0-5 VDC, 0-10 VDC, or 4-20 mA output signal.

The meter electronics are packaged in an anodized aluminum NEMA
2 or a painted cast aluminum NEMA 4 enclosure. The electronics are
mounted either directly on the sensing probe or for NEMA 2 enclo­sures, remotely up to 100 feet (60 meters) away.

Accu-Mass™ Sensor

Heat

Gas temperature sensor

Heated velocity sensor

Mass flow

Figure 1. Series 730 Accu-Mass Sensor Probe

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