Xylem H-312-22 User Manual

Model

H-312 and H-312-22

Submersible Pressure Sensor

With SDI-12 Output

Owner's Manual

Version 1.1

75 West 100 South, Logan, Utah 84321 Phone: [phone] Fax: [phone] Web: http://www.waterlog.com E-mail: [e-mail]

D E S I G N A N A L Y S I S A S S O C I A T E S , I N C .

75 West 100 South, Logan, Utah 84321 Phone: [phone] Fax: [phone] Web: http://www.waterlog.com E-mail: [e-mail]

D E S I G N A N A L Y S I S A S S O C I A T E S , I N C .

User Agreement/

W

ATER

1. NATURE OF THE PRODUCT

This agreement accompanies a pressure measuring system comprising firmware, circuitry and other
electronic equipment in an enclosed housing, and packaged together with written instructional materials.
The packaged electronic circuitry and instructional materials herein are collectively referred to as the
“PRODUCT.” The PRODUCT is made available from DESIGN ANALYSIS ASSOCIATES, INC., of
75 West 100 South, Logan, Utah 84321 (hereinafter referred to as “DESIGN ANALYSIS”), and contains
information and embodies technology that is confidential and proprietary to DESIGN ANALYSIS, and the
availability and use of the PRODUCT is extended to you, the USER, solely on the basis of the terms of
agreement which follow.

2. ACKNOWLEDGMENTS BY USER

Opening the package which encloses the accompanying PRODUCT indicates your acceptance of the terms
and conditions of this agreement and constitutes an acknowledgment by you of the confidential and
proprietary nature of the rights of DESIGN ANALYSIS in the PRODUCT.

3. DUTIES OF YOU, THE USER

In consideration for the access to and use of the PRODUCT extended to you by DESIGN ANALYSIS and
to protect the confidential and proprietary information of DESIGN ANALYSIS, USER agrees as follows:

(a) USER agrees that they will not remove from the exterior of the housing of the PRODUCT

any safety warnings or notices of proprietary interest placed thereon by DESIGN
ANALYSIS.

LOG® Warranty

(b) USER agrees that they shall not disassemble or otherwise reverse engineer the

PRODUCT.

(c) USER agrees to treat the PRODUCT with the same degree of care as USER exercises in

relation to their own confidential and proprietary information.

4. TERM

USER may enjoy these rights only as long as their possession of the PRODUCT shall continue to be
rightful. These rights will cease if the PRODUCT is returned to DESIGN ANALYSIS under the terms of
any redemption offer, warranty, or money-back guarantee, or if USER transfers the PRODUCT to another
party on terms inconsistent with this agreement.

5. LIMITED WARRANTY
(a) What is Covered

DESIGN ANALYSIS warrants that for a period of twelve months from the time of delivery the
functions to be performed by the PRODUCT will be substantially in compliance with USER
documentation. DESIGN ANALYSIS also warrants that the PRODUCT will be free from defects
in materials and workmanship for a period of ONE YEAR from the date of delivery.

(b) What USER Must Do

If the product fails to satisfy the above warranty, USER must notify DESIGN ANALYSIS in

H-312

User Agreement/W

ATER

LOG® Warranty W-1

writing within the applicable period specified above and reasonably cooperate with the directions
they received from DESIGN ANALYSIS.

(c) What DESIGN ANALYSIS Will Do

DESIGN ANALYSIS will repair the PRODUCT or will endeavor to provide a replacement of
same within a reasonable period of time. In the event that DESIGN ANALYSIS is unable to make
the necessary repairs or replacement within a reasonable period of time, the original purchase price
will be refunded upon the return of the PRODUCT to DESIGN ANALYSIS.

(d) Limitations

(i) THE ENTIRE REMEDY FOR BREACH OF THIS LIMITED WARRANTY

SHALL BE LIMITED TO REPLACEMENT OF THE DEFECTIVE
PRODUCT OR REFUNDING OF THE PURCHASE PRICE, AS SET FORTH
ABOVE. IN NO EVENT WILL THE LIABILITY OF DESIGN ANALYSIS
TO USER OR TO ANY OTHER PARTY EXCEED THE ORIGINAL
PURCHASE PRICE OF THE PRODUCT, REGARDLESS OF THE FORM OF
THE CLAIM.

(ii) EXCEPT FOR THE EXPRESS WARRANTIES ABOVE, DESIGN ANALYSIS

SPECIFICALLY DISCLAIMS ALL OTHER WARRANTIES, INCLUDING,
WITHOUT LIMITATION, ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

(iii) UNDER NO CIRCUMSTANCES WILL DESIGN ANALYSIS BE LIABLE

FOR SPECIAL, INCIDENTAL, CONSEQUENTIAL, INDIRECT, OR ANY
OTHER DAMAGES OR CLAIMS ARISING FROM THE USE OF THIS
PRODUCT, THIS INCLUDES LOSS OF PROFITS OR ANY OTHER
COMMERCIAL DAMAGES, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES. IN NO EVENT WILL DESIGN ANALYSIS BE LIABLE
FOR ANY CLAIMS, LIABILITY, OR DAMAGES ARISING FROM
MODIFICATION MADE THEREIN, OTHER THAN BY DESIGN
ANALYSIS.

(iv) THIS LIMITED WARRANTY GIVES USER SPECIFIC LEGAL RIGHTS.

USER MAY ALSO HAVE OTHER RIGHTS WHICH VARY FROM STATE
TO STATE. SOME STATES DO NOT ALLOW LIMITATIONS ON HOW
LONG AN IMPLIED WARRANTY LASTS OR THE EXCLUSION OF
INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THOSE
LIMITATIONS OR EXCLUSIONS MAY NOT APPLY.

6. GOVERNING LAW

This Agreement and its validity and interpretation shall be governed by the laws of the State of Utah,
notwithstanding any choice of law rules of Utah or any other state or jurisdiction.

W-2 User Agreement/W

ATER

LOG® Warranty

H-312

1.0 Introduction

Chapter 1

Introduction

The W
level monitoring. The H-312 is easy to use and works with any SDI-12 data recorder. The
“Serial-Digital Interface” is ideal for data logging applications with the following requirements.

 Battery powered operation with minimal current drain
 Pressure measurement data is transmitted digitally over long cable lengths without error
 Multiple sensors on a simple three-wire cable
 Up to 250 feet of cable between a sensor and the data recorder

The H-312 has the following features:

 Simple to install, use, and maintain (no on-site calibration required)
 Performs extremely accurate measurements.
 Linear deviation is less than 0.05%
 Resolution is 1 part in 1,000,000
 Accuracy over temperature range exceeds ±0.02 ft. of water
 Enclosure is nonconductive and corrosion proof
 Stainless steel sensor diaphragm
 Sensor cable has internal atmospheric vent for compensation of barometric pressure changes
 Junction box provides access for inspection and maintenance of dry-air desiccant
 Low current operation (less than 150 microamps typical standby)
 Suspension bail provides positive control of the sensor depth independent of temperature and

 Extended SDI-12 commands for setting the Stage to the current water elevation.

ATER

LOG® H-312 is a submersible pressure transducer specifically designed for water

(Use of H-423, SDI-12 to RS485 converter extends the range to 1000's of feet)

age dependent changes to the sensor cable.

H-312

Introduction 1-1

1.1 Unpacking

The following is a list of items you should have received:

ATER

 W

junction box

 Stainless steel ballast
 Spare desiccant packs
 Owner's Manual
 Stainless steel suspension cable and miscellaneous hardware (optional)

LOG® H-312 pressure transducer with polyurethane vented cable and dry air

1-2 Introduction

Figure 3 H-312 Pressure Sensor Components

H-312

1.2 Check The Sensor Cable

Be sure that the vented cable is long enough to reach from the submerged location selected to the
junction box of the dry air system. Also, be sure that the data logger cable is long enough to
reach from the dry air junction box to your data recorder

1.3 Check The Model Number

Before installing your new W
enclosure. Check the model number, the range, and the output type to be sure that you have
received the instrument you ordered. The label will look similar to the following:

ATER

LOG® H-312, check the information on the label of the sensor

H-312

Model

Submersible Pressure Sensor

S/N 1103
Range: 0-15 PSI (34.6' H20)
Output:: SDI-12
Input: 10 to 16.0 Volts

that the W
model works with a recording device that follows the SDI-12 protocol.

ATER

LOG® H-312-15 measures pressure within the range from zero to 15 psi. This

.

This example shows

H-312

Introduction 1-3

1-4 Introduction

H-312

Chapter 2

Installation

ATER

2.1 Installing the W

The H-312 submersible pressure sensor is very versatile and can be used in many water
monitoring applications.

LOG® H-312

Figure 4 H-312 System Components

Before proceeding with the installation, please consider several site preparation and maintenance
issues:

H-312

Installation 2-1

2.2 Water Depth

The following chart shows the maximum depth to which the H-312 is factory calibrated. The
sensor can survive temporary operation up to twice the maximum rated depth for you model’s
range. However, any pressure measurements made beyond the rated depth will be inaccurate.
The H-312 will be damaged if it is placed deeper than twice the maximum rated depth.

Model Pressure Range Depth Range

*

Accuracy
H-312-15 0 to 15 psi 0 to 34.60 ft. +0.017 ft
H-312-30 0 to 30 psi 0 to 69.20 ft. +0.035 ft.

* NOTE: Depth calculations are derived from the standard equation that one PSI is generated by
a column of water 27.680 inches deep at 39.4F.

2.3 General Installation Recommendations

The sensor must be located where there is no velocity flow. Changes in water flow cause pressure
changes. Thus, if the sensor is subjected to open flow there is a good chance your water level
measurements will be inconsistent. To obtain accurate and reliable data, use stilling wells, sand
points, or other "no flow" installation techniques.

The H-312 submersible pressure transducer is not recommended for use in applications where silt
and mud are problematic. In addition, if the sensor is used in a shallow water application and
happens to dry out with mud coating the sensor diaphragm, the diaphragm compliance will be
altered and the factory calibration spoiled.

The H-312 sensor will be permanently damaged if it is frozen. Transducers which are installed in
geographical areas with harsh winters should be removed for the winter unless they are installed
deep enough in the water that there is no danger of freezing. Ice may form around the sensor
cable without causing damage or performance degradation. However, the cable should be
protected so as to minimize the possibility of it being damaged as the ice shifts or breaks up
during times of thawing.

The polyurethane drop cable is suitable for immersion, direct burial and is somewhat ultraviolet
(UV) resistant. Whenever possible, precautions should be taken to protect the cable from direct
sunlight, rodents and mechanical damage.

Experience has shown that if a portion of the H-312 housing or the sensor cable is installed above
the water and exposed to sunlight (e.g. installed in shallow water), a temperature gradient can
occur inside the enclosure and vent tube. As the air temperature changes the air density changes.
A change in the air density inside the sensor or vent tube column causes a partial pressure on the
reference side of the sensor which will raise or lower the H-312's pressure reading. This is a "law
of physics" problem not unique to W

ATER

LOG® Series transducers. It can be avoided by

installing the transducer horizontal so that the entire enclosure is covered by water. Cover or

2-2 Installation

H-312

protect the sensor cable so it remains at the temperature of the surrounding air and is not heated
directly by the sun.

2.4 Stilling Wells

The H-312 can be hung in well bores, stilling wells and stand­pipes. The H-312 should be installed by suspending the sensor
using a small stainless steel cable, not by its polyurethane
electrical cable. A weighted ballast or sinker, such as the one
that is provided will pull the cable tight at the desired depth and
will help the sensor to hang straight down. The stainless cable
and the miscellaneous hardware can be purchased from Design
Analysis Associates, or from a number of other sources.

The polyurethane cable has internal kevlar strength members
however, the plastic cable construction has a large thermal
coefficient of expansion. This coupled with the fact that the
cable will stretch with applied weight, make the use of the
stainless steel drop cable necessary for all precision
measurements.

Attach one end of the stainless steel support cable to the
support bail on the sensor and fasten the other end to a fixed
reference point at the surface. Attach the ballast to the sensor
using the stainless steel ring on the bottom nose of the sensor.

When installing the H-312 in wells or stand pipes, make certain
the surface of the water in the pipe is open to the atmosphere.
Well pipes are often capped with a sanitary well seal or locking
cap, make certain the well cap has a suitable hole or screened
vent.

H-312

Installation 2-3

2.5 Dry Air Junction Box

Because the surface of the water being measured is exposed to atmospheric pressure, submersible
pressure sensors must provide correction for changes in barometric air pressure. Several industry
designs employ a sealed sensor housing and measure the atmospheric pressure separately. This
scheme however, doubles the offset drift because two pressure sensors are needed. To provide
the best accuracy possible, the H-312 uses an atmospheric referenced pressure sensor design. The
submerged pressure sensor in the H-312 has a vent tube connected to the back side it’s pressure
diaphragm.. The vent tube passes up the drop cable and is open to the atmosphere at the top.
Vent tube designs however, are susceptible to moisture condensation in the tube. As the
atmospheric pressure changes small amounts of air flow up and down the vent tube. Convection
can also contribute to airflow within the vent tube. If the vent tube is colder than the dew point of
the air, moisture will condense in the tube. This condition occurs continually because the
submerged portion of the vent tube is maintained at the water temperature. The temperature of
both surface and ground water are normally well below the dew point of the surrounding air.

The H-312 dry air junction box
provides for terminating the
polyurethane sensor cable and
houses desiccant for keeping the
atmospheric vent tube dry. The
enclosure has a transparent lid
which allows visual inspection of
the desiccant packs. The
enclosure has a small screened
vent port in the top cover which
exposes the sensor vent tube to
the atmosphere.

Figure 6 Dry Air Junction Box

The dry air junction box should
be installed in a protected, dry,
location such as an instrument shelter. The installation should provide easy access and facilitate
regular inspection and maintenance of the desiccant.

2.6 Making Connections to the H-312

The H-312 is a SDI-12 V1.2 compliant sensor. It connects directly to any data recorder with
SDI-12 capability. The dry air junction box has a 4-conductor pigtail cable for making
connections to your data logger. The pigtail cable can be modified or replaced in the field. The
table below shows the proper connections to the pigtail. The power for the H-312 is supplied by
the SDI-12 +12V input. The connections are also shown on a wiring diagram inside the dry air
junction box.

2-4 Installation

H-312