Ashcroft A4A User Manual

• Slotted Link – is recommended for applications where gauge will
be subjected to sudden release of pressure such as burst test­ing.The slotted link option protects the movement from damage
due to rapid pressure decrease.

•

Peak Load Indicator – tracks pressure change and provides indi­cation of maximum pressure measured.

•

Wall Mounting Brackets – 3 factory installed brackets allow
gauge to be mounted to any flat service without the need for a
panel cutout.

STORAGE REQUIREMENTS

Gauges should be stored in a sealed plastic bag and k
clean dr

y area.Whenever possible the gauge should be stored in

ept in a

the original carton and packing material. Storage temperatures
should be in the range of –25 to +125°F.

SHELF LIFE INFORMATION

When proper

ly stored, no shelf life limitations will apply. However,
if the gauge is in storage in excess of one year, it is recommended
that the gauge be recertified prior to use.These gauges do not
contain rubber, plastic or any other soft materials subject to drying
and/or cracking.There are no O-rings or elastomer seals.

SPECIAL HANDLING REQUIREMENTS

This is a high precision gauge.As with any precision test equipment
it should be handled with care to assure its accuracy is maintained.

FOR A COMPLETE OPERATION AND MAINTENANCE USER’S
MANUAL CONTACT THE FACTORY CUSTOMER SERVICE
DEPARTMENT.

Installation
and
Operating
Instructions

ASHCROFT®Model A4A
Precision Pressure Gauge

Rev.5 01/06

Ashcroft Inc.
250 East Main Street
Stratford, CT 06614
Tel.: [phone]
Fax:[phone]
email: [e-mail]

oft.com

.ashcr

www

© 2006 Ashcroft Inc. All rights reserved.
All sales subject to standard ter
250 East Main Street, Stratford, CT 06614
T

el: 203-378-8281, Fax:[phone], www.ashcroft.com

I&M002-10126-5/004 Re

ms and conditions of sale.

5, 1CAMR 2/07

.

v

I&M002-10126-5/004 Rev. 5, 1CAMR 2/07

SAFETY PRECAUTIONS

Pressure gauge selection should be done in accordance with
recognized industry codes and safety practices to avoid the possi­bility of misuse or misapplication which could result in personal in­jury or damage to property. ASME B40.1 should be consulted by
those responsible for gauge selection and installation.

UNP ACKING THE GAUGE

All Ashcroft®A4A precision pressure gauges are shipped with a
piece of foam between the glass window and the pointer. This
foam secures and protects the movement from damage during
shipment.

THIS FOAM MUST BE REMOVED PRIOR TO INSTAL-

LATION AND OPERATION OF THE GAUGE

To remove foam, first remove the zero adjust lock screw located
beneath the dial face.This is the screw located in the center of the
zero adjust knob.With this screw removed lift the bottom of the
bezel away from the gauge.Then lift the bezel up and off the align­ment pin at the top of the gauge

.With bezel assemb

ly off, remove
pad. Reinstall bezel through reverse procedure. Be certain to align
the teeth for zero adjust mechanism prior to replacing dial adjust

w.

k scre

loc

GAUGE INSTALLA

TION

Unless otherwise specified at the time of order, Ashcroft®A4A

tical position. Gauges

gauges are calibr

ated in the upright or v

er
should always be mounted in the same position as they were cali­brated to eliminate positional errors.Special calibration is required
for gauges to be mounted in any position other than vertical. Each
gauge has three holes for

1

⁄

4˝ screws spaced 120° apart on the

back of the bezel to facilitate panel mounting. Factory installed wall
mounting brackets are available as an option.

GAUGE OPERATION

Ashcroft®A4A gauges are precision instruments. Certain proce­dures and precautions are recommended in order to maximize
their performance.These are:

For liquid systems the trapped air should be purged from the sys-

When

tem using the b

leeder cap on the end of the Bourdon tube

.
opening or closing the bleeder cap firmly hold the free end of the
Bourdon tube to protect the movement, Bourdon tube or linkages

To bleed air from system open bleeder

from damage due to stress

.
cap slightly and carefully apply pressure to the gauge to force fluid
through the cap.Allow the fluid to flow for several seconds to
purge tr

apped gas from the tube

. Direct the fluid away from the

gauge to protect the movement from becoming contaminated.
Once this is done tighten cap.

It is good practice to pressurize the gauge to full scale for several
minutes prior to use.The pressure should then be removed and
the dial zeroed, if necessary.The dial adjuster is located at the
bottom of the dial.The smaller central knob is an adjustment lock
and the larger, outer knob is used for zero adjustment.

PRESSURE MEDIA

Care should be taken to assure that the process pressure media
are compatible with the gauge wetted materials.Hydrogen use
should be limited to gauges equipped with Beryllium Copper
Bourdon tubes.Consult factory for questions regarding media
compatibility.

Unless specially cleaned, the gauge wetted surfaces may include
cleaning solvent or hydrocarbon (oil) residue from the manufactur­ing and calibration processes.These substances may be incom­patible with specific installations or process media.Consult factory
for special f

actory cleaning options

.

DO NO

T USE GA

UGES ON
OXYGEN SERVICE UNLESS GAUGE HAS BEEN CLEANED
AND CERTIFIED FOR OXYGEN USE.

Failure to comply with
these recommendations could result in damage to the gauge and
personal injury.

GAUGE ACCURACY & CALIBRATION

Ashcroft®A4A precision pressure gauges are calibr

ated at the fac
tory to ±0.1% F.S. accuracy and certified, traceable to the N.I.S.T.,
USA. (Note: For gauges equipped with 316 SS Bourdon tubes,
hysteresis may exceed 0.1% and is not guaranteed).Primary cali­bration adjustments on the movement are sealed with liquid metal
and should not be altered.Tampering with these calibration points
may degrade the accuracy of the gauge and will void the warranty.

Under normal operation, a one-year calibration cycle is recom-

®

mended for your Ashcroft

A4A precision pressure gauge(s).

Recertification services are available at the factory.

OPTIONAL FEATURES

mal Compensation

• Bimetallic

Ther

– is recommended f

gauges that are to be installed in non-temper

ature controlled en

or all

vironments. This option maintains the 0.1% of span accuracy
over a range of –25 to +125°F.Gauges not equipped with this op­tion ma

y incur an additional 0.1% error per 5

°F deviation outside

the operating temperature window of 68-72°F.

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