OfiTE 131-50 Instruction Manual

Electrical Stability Meter

Instruction Manual

11302 Steeplecrest Dr. · Houston, Texas · 77065 · U.S.A.

Tele: 832.320.7300 · Fax: [phone] · www.ote.com

Part No. 131-50

Updated 12/10/2015

Ver. 3.0

OFI Testing Equipment, Inc.

©

Copyright OFITE 2012

Table of

Intro..................................................................................................2

Description ...................................................................................... 2

Contents

Components ...................................................................................3

Specications .................................................................................4

Procedure ........................................................................................ 5

Calibration - Performance Test ..................................................... 6

Warranty and Return Policy ..........................................................7

OFITE, 11302 Steeplecrest Dr., Houston, TX 77065 USA / Tel: [phone] / Fax: [phone] / www.ote.com

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Intro

The OFITE Electrical Stability Meter (ES) is a sine wave instrument. It is
manufactured in accordance with the American Petroleum Institute (API)
“Recommended Practice Standard Procedure for Field Testing Oil-Based
Drilling Fluids”, 13B-2. It is accurate, compact, and portable and is intended

for routine eld and laboratory use to measure the relative electrical strength
of drilling uids having a continuous oil phase.

The ES Meter is self contained and consists of a meter and probe, and it
operates on four 9 volt alkaline batteries which are readily obtainable. Two
calibration standards (high and low) are included with each unit to ensure ac­curacy.

Description

The dielectric breakdown voltage is the point at which the drilling uid be­comes electrically conductive. The DC power source of the batteries pro­vides an AC voltage to the electrodes at a low frequency. The unit provides a
constant rate of voltage increase until the emulsion becomes electrically con-

ductive. A current ow of 61 micro amps (61 mA) across the electrodes will

cause the display to stop and the reading will be held as long as the switch is
depressed. The reading is called the electrical stability, emulsion stability or

ES value of the uid.

The electrical stability value will decrease with increasing testing temperature.
The recommended API test temperature is 120°F ± 5° (49°C ± 3°).

The chemical composition and the shear history of a drilling uid control the

absolute magnitude of the ES in a complex fashion. Therefore, interpreting
the oil-wet state of a mud from a single ES measurement is not appropriate.
Only trends in ES should be used in making treatment decisions.

OFITE, 11302 Steeplecrest Dr., Houston, TX 77065 USA / Tel: [phone] / Fax: [phone] / www.ote.com

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