APG LPU-2127 User Manual

PRODUCTS

AUTOMATION

Operator’s Manual

GROUP, INC.

LPU-2127

Rev. A5, 1/14

APG...Providing tailored solutions for measurement applications

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Automation Products Group, Inc.

LPU-2127 Rev. A5, 1/14

Table of Contents

Warranty ......................................................................................... 3

Introducing...................................................................................... 4

Understanding Ultrasonics ............................................................. 5

Installation ...................................................................................... 7

Hazardous Mounting.................................................................... 8

Wiring.............................................................................................. 9

Programming ................................................................................ 10

Operation ................................................................................... 11

Calibration ................................................................................. 13

Utilities ...................................................................................... 14

Mode Sheet ................................................................................... 16

Specifications ................................................................................ 19

Certificate of Compliance ............................................................ 20

Automation Products Group, Inc.

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APG...Providing tailored solutions for measurement applications

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Rev. A5, 1/14 LPU-2127

• Warranty and Warranty Restrictions

APG warrants its products to be free from defects of material and workmanship
and will, without charge, replace or repair any equipment found defective upon
inspection at its factory, provided the equipment has been returned,
transportation prepaid, within 24 months from date of shipment from factory.

THE FOREGOING WARRANTY IS IN LIEU OF AND EXCLUDES ALL OTHER
WARRANTIES NOT EXPRESSLY SET FORTH HEREIN, WHETHER
EXPRESSED OR IMPLIED BY OPERATION OF LAW OR OTHERWISE
INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

No representation or warranty, express or implied, made by any sales
representative, distributor, or other agent or representative of APG which is not
specifically set forth herein shall be binding upon APG. APG shall not be liable
for any incidental or consequential damages, losses or expenses directly or
indirectly arising from the sale, handling, improper application or use of the
goods or from any other cause relating thereto and APG’s liability hereunder, in
any case, is expressly limited to the repair or replacement (at APG’s option) of
goods.

Warranty is specifically at the factory. Any on site service will be provided at
the sole expense of the Purchaser at standard field service rates.

All associated equipment must be protected by properly rated electronic/
electrical protection devices. APG shall not be liable for any damage due to
improper engineering or installation by the purchaser or third parties. Proper
installation, operation and maintenance of the product becomes the
responsibility of the user upon receipt of the product.

Returns and allowances must be authorized by APG in advance. APG will
assign a Return Material Authorization (RMA) number which must appear on
all related papers and the outside of the shipping carton. All returns are subject
to the final review by APG. Returns are subject to restocking charges as
determined by APG’s “Credit Return Policy”.

Automation Products Group, Inc.

APG...Providing tailored solutions for measurement applications

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3

LPU-2127 Rev. A5, 1/14

Introducing

The LPU series are loop-powered ultrasonic sensors. The LPU provides a
low-power non-contact level measurement solution. These units are provided
with 4-tactile switches and a 4-digit LCD display to provide the user feedback
in programming and sensor performance data.

Sensor features include:

• Loop powered for low power consumption.

• Built-in keypad and display for easy setup and distance readings.

• Rugged Kynar transducer housing for harsh environments and high degree
of chemical compatibility.

• Microprocessor-controlled.

• Listed by CSA for operation in Class 1 Division 2 Groups C & D and Class
1 Zone 2 A Ex nA IIB hazardous areas.

• NEMA 4X rating for outdoor applications.

Automation Products Group, Inc.

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APG...Providing tailored solutions for measurement applications

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Rev. A5, 1/14 LPU-2127

detection

area

beam spread

low sensitivity
and
pulses

high sensitivity
and
pulses

Understanding Ultrasonics

Ultrasonic sensors measure distance
using a transducer to send out
ultrasonic bursts. Each burst contains a
series of 1-20 pulsed sound waves that
emit in the shape of a cone, reflect off
the target, and are received by the
sensor. The time required for the sound
burst to travel to and from the target is
converted into a distance measurement
by the sensor.

Ultrasonic sensing is affected by
several factors including the target
surface, distance, size, and angle. The
following considerations will help
ensure the best possible target
conditions.

Surface

The ideal target surface is hard and smooth and perpendicular to the sensor.
This surface will reflect a greater amount of signal than a soft, sound wave
absorbent surface. A target with poor sound wave reflection characteristics will
reduce the operating distance of the sensor and decrease its accuracy.

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LPU-2127 Rev. A5, 1/14

Distance

The shorter the distance from the sensor to an object, the stronger the
returning echo will be. Therefore, as the distance increases, the object requires
better reflective characteristics to return a sufficient echo.

Size

A large object will have a greater surface area to reflect the signal than a
small one, therefore, a large target will be detected at a greater distance than a
small target. The surface area recognized as the target is generally the portion
closest to the sensor.

Angle

The inclination of the object's surface facing the ultrasonic sensor affects the
reflectivity of the object. The portion perpendicular to the sensor returns the
echo. If the entire surface is at a great enough angle, the signal will be reflected
away from the sensor and no echo will be detected. Generally a target at an
angle greater than 5 degrees off perpendicular will not be detected.

Automation Products Group, Inc.

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Rev. A5, 1/14 LPU-2127

DO NOT mount the sensor
where the beam will intersect
objects such as fill streams,
pipes, ladder rungs, wall seams,
or corrugated tank walls.

Installation

The LPU sensor should be mounted so that it has a clear sound path to the
level monitored. Mount the sensor away from tank walls and inlets. The path
should be free from obstructions and as open as possible for the 9° off axis
beam pattern. Follow the guidelines mentioned in "Understanding
Ultrasonics", earlier in this manual. When using a stand pipe to mount the
sensor above the tank, the stand pipe should be seamless and no longer than 4
inches to provide a smooth path for the sound waves to propagate into the
tank. Seams from couplers, nipples or gaskets can cause erroneous echoes and
degrade the sensors performance. The LPU can be mounted in a coupler, or
flange using the 2” NPT threaded case.

Caution: Do not over tighten! The sensor should be threaded in only hand
tight.

The minimum detection range of the LPU is approximately 1 ft. The sensor
should be mounted to ensure the target does not come closer than the
minimum range or erroneous readings may result.

See the Hazardous Mounting section of this manual before mounting the
LPU sensor in a hazardous area.

APG...Providing tailored solutions for measurement applications

Tel: [phone] • Fax: [phone] • www.apgsensors.com • [e-mail]

Automation Products Group, Inc.

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LPU-2127 Rev. A5, 1/14

Automation Products Group, Inc.

APG...Providing tailored solutions for measurement applications

8

Tel: [phone] • Fax: [phone] • www.apgsensors.com • [e-mail]

Rev. A5, 1/14 LPU-2127

4.25

Ammeter

COM

mA

Power Supply
(24Vdc)

+

-

4 to 20ma Out

+24vdc

Load Resistance
or Input Card

Wiring

Cable Entry

1. Remove the cable knock out with

lid closed.

2. Clear flashing.

3. Open lid.

4. Install cable gland or conduit

connection.

5. Connect cable as shown:

12 to 28 VDC to (+) Terminal
4 to 20 ma output to (-) Terminal

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Automation Products Group, Inc.

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