Rosemount 1181-SO Dissolved Oxygen Transmitter Owner's manual

Brand: Rosemount

Model: 1181-SO Dissolved Oxygen Transmitter

Category: Oxygen Equipment

Type: Owner's manual

Model 1181SO

Dissolved Oxygen Two-Wire Transmitter

Instruction Manual

PN 51-1181SO/rev.A

April 2003

ESSENTIAL INSTRUCTIONS

READ THIS PAGE BEFORE PRO-

CEEDING!

Rosemount Analytical designs, manufactures, and tests its

products to meet many national and international stan-

dards. Because these instruments are sophisticated tech-

nical products, you must properly install, use, and maintain

them to ensure they continue to operate within their normal

specifications. The following instructions must be adhered

to and integrated into your safety program when installing,

using, and maintaining Rosemount Analytical products.

Failure to follow the proper instructions may cause any one

of the following situations to occur: Loss of life; personal

injury; property damage; damage to this instrument; and

warranty invalidation.

• Read all instructions prior to installing, operating, and

servicing the product. If this Instruction Manual is not the

correct manual, telephone 1-800-654-7768 and the

requested manual will be provided. Save this Instruction

Manual for future reference.

• If you do not understand any of the instructions, contact

your Rosemount representative for clarification.

• Follow all warnings, cautions, and instructions marked

on and supplied with the product.

• Inform and educate your personnel in the proper instal-

lation, operation, and maintenance of the product.

• Install your equipment as specified in the Installation

Instructions of the appropriate Instruction Manual and

per applicable local and national codes. Connect all

products to the proper electrical and pressure sources.

• To ensure proper performance, use qualified personnel

to install, operate, update, program, and maintain the

product.

• When replacement parts are required, ensure that qual-

ified people use replacement parts specified by

Rosemount. Unauthorized parts and procedures can

affect the product’s performance and place the safe

operation of your process at risk. Look alike substitu-

tions may result in fire, electrical hazards, or improper

operation.

• Ensure that all equipment doors are closed and protec-

tive covers are in place, except when maintenance is

being performed by qualified persons, to prevent electri-

cal shock and personal injury.

DANGER

HAZARDOUS AREA INSTALLATION

INTRINSICALLY SAFE INSTALLATION

Installations in hazardous area locations

must be carefully evaluated by qualified

on site safety personnel. Transmitter and

Sensor alone are not

Intrinsically safe. To

secure and maintain an intrinsically safe

installation, a certified safety barrier must

be used and the installation must comply

with the governing approval agency (FM,

CSA or BASEEFA/CENELEC) installation

drawing requirements (see Section 2.0 -

Installation).

EXPLOSION-PROOF INST

ALLATION

Caution: Sensors are not explosion-proof. If

the sensor must be installed in a hazardous

location an intrinsically safe system must be

implemented.

To maintain the explosion-proof rating of the

transmitter, the following conditions must be

met:

• Discontinue power supply before

removing enclosure covers.

• Transmitter covers must be properly

installed during power on operation.

• Explosion proof "Y" fittings must be

properly installed with sealing com-

pound prior to applying power to the

transmitter.

• Serial tag cover over the external Zero and

Span adjustments must be in place.

• See Installation Section for details.

Proper installation, operation and servicing

of this instrument in a Hazardous Area

Installation is entirely the responsibility of

the user.

Emerson Process Management

Rosemount Analytical Inc.

2400 Barranca Parkway

Irvine, CA 92606 USA

Tel: (949) 757-8500

Fax: (949) 474-7250

http://www.RAuniloc.com

MODEL 1181SO TABLE OF CONTENTS

MODEL 1181SO

DISSOLVED OXYGEN TWO-WIRE TRANSMITTER

TABLE OF CONTENTS

Section Title Page

1.0 DESCRIPTION AND SPECIFICATIONS.............................................. 1

1.1 Features and Applications .................................................................... 1

1.2 Performance Specifications.................................................................. 2

1.3 Ordering Information............................................................................. 3

2.0 INSTALLATION..................................................................................... 4

2.1 Unpacking and Inspection .................................................................... 4

2.2 Mechanical Installation ......................................................................... 4

2.3 Sensor Installation ................................................................................ 4

2.4 Electrical Installation............................................................................. 4

2.5 Hazardous Locations-Explosion Proof Installation ............................... 6

2.6 Hazardous Locations-Intrinsically Safe Installation .............................. 6

3.0 CONFIGURATION, START-UP AND CALIBRATION........................... 16

3.1 General................................................................................................. 16

3.2 Configuration ........................................................................................ 16

3.3 Start up ................................................................................................. 16

3.4 Span Calibration ................................................................................... 18

4.0 OPERATION AND DESCRIPTION OF CONTROLS............................ 22

4.1 Theory of Operation.............................................................................. 22

4.2 Measurement Variables........................................................................ 23

4.3 Description of Controls ......................................................................... 24

4.4 Converting to an LCD unit .................................................................... 26

5.0 DIAGNOSTICS AND MAINTENANCE ................................................. 27

5.1 General................................................................................................. 27

5.2 Disassembly Procedure........................................................................ 27

5.3 Reassembly Procedure ........................................................................ 27

5.4 Troubleshooting .................................................................................... 28

5.5 1181SO Operation Check..................................................................... 29

6.0 SPARE PARTS ..................................................................................... 30

6.1 Spare Parts........................................................................................... 30

7.0 RETURN OF MATERIALS.................................................................... 34

7.1 General................................................................................................. 34

7.2 Warranty Repair.................................................................................... 34

7.3 Non Warranty Repair ............................................................................ 34

MODEL 1181SO TABLE OF CONTENTS

TABLE OF CONTENTS CONT’D.

LIST OF FIGURES

Figure No. Title Page

2-1 Mounting and Dimensional Drawing..................................................... 5

2-2 Model 1181 SO Wiring Details ............................................................. 7

2-3 FM Explosion Proof Installation............................................................ 8

2-4 FM Intrinsically Safe Installation and Entity Parameters........................ 9

2-5 CSA Intrinsically Safe Installation......................................................... 12

2-6 CENELEC Intrinsically Safe Installation ............................................... 13

3-1 Calibration Set Up ................................................................................ 17

3-2 Calibration with Agitated Fresh Water.................................................. 21

4-1 Oxygen Solubility in Fresh and Sea Water .......................................... 22

4-2 Location of Controls.............................................................................. 25

4-3 1181SO LCD Meter Option -06 ............................................................ 26

5-1 1181SO Operation Check Up............................................................... 29

6-1 1181SO Parts Breakdown .................................................................... 31

6-2 1181 SO Transmitter PCB .................................................................... 32

6-3 1180 SO Transducer PCB .................................................................... 32

6-4 1180 SO Power Supply PCB................................................................ 33

6-5 1181 SO PCB Stack ............................................................................. 33

LIST OF TABLES

2-1 Wiring Model 1181 SO to Model Hx438 and Gx448 sensors .............. 7

3-1 Range -vs- Dip Switch Position............................................................ 18

3-2 Water Vapor Partial Pressure ............................................................... 20

3-3 Solubility of Oxygen.............................................................................. 20

4-1 LCD Decimal Point Set Up................................................................... 26

5-1 Troubleshooting Guide ......................................................................... 28

MODEL 1181 SO SECTION 1.0

GENERAL DESCRIPTION AND SPECIFICATIONS

1.1 FEATURES AND APPLICATIONS

The Rosemount Analytical Two-Wire field mounted

transmitters, with the appropriate sensors, are designed

to continuously measure the pH, ORP, Conductivity,

Dissolved Oxygen, or Free Residual Chlorine in industri-

al processes.

The Model 1181 Transmitters include all the circuitry nec-

essary for the measurement and transmission of an iso-

lated 4-20 mA linear signal. Measurement range selec-

tion is made through internal range switches that are

easily accessed by removing a housing cover. No further

disassembly is required. A matrix is provided which con-

veniently indicates the proper switch position. Range

selection can be made without the use of the instruction

manual. Fine calibration of the 4-20 mA signal is accom-

plished with the 20-turn external Zero and Span poten-

tiometers.

The electronic printed circuits are protected from the envi-

ronment by the NEMA 4X weatherproof, corrosion resist-

ant enclosure. The printed circuit cards plug into a mois-

ture barrier which is isolated from the field wiring and cali-

bration terminals. Routine field calibration does not require

exposing the electronics to harsh industrial environments.

All PCBs are conformal coated for maximum protection.

The PCBs are removed as a unit and may be individually

replaced. The transmitter housing covers are sealed with

large cross sectional O-rings and need not be replaced

each time the cover is removed.

The Model 1181 is available with or without an analog or

digital display. The digital display may be calibrated in

engineering units and the analog display features multi-

ple scales in engineering units.

The transmitters are certified explosion-proof, NEMA 7B,

and intrinsically safe when installed with an approved

barrier and sensor. Hazardous area certificates are pro-

vided by BASEEFA to CENELEC regulations, FM and

CSA.

Accessory items are available for the two-wire transmit-

ters. The Model 515 Isolated Power Supply provides

power for up to 20 transmitters. Two transmitters may be

wired directly to the power supply. For more than two

transmitters, junction boxes are available, each accom-

modating wiring for a maximum of ten transmitters.

Remote alarms are available with independently

adjustable set points and hysteresis. Contacts of the

Model 230A may be specified for high/low, high/high, or

low/low operation. The impedance of the Model 230A

Alarm Module is less than 100 ohms. For further infor-

mation on the Models 515 and 230A, please refer to to

their respective product data sheet.

The Model 1181SO Transmitter is designed for use with

the Models Hx438 and Gx448 Steam Sterilizable

Dissolved Oxygen Sensors used for sanitary applica-

tions in food, beverage, and pharmaceutical industries.

Switch selectable measurement ranges are 0-100, 0-

200 and 0-800 mm Hg. The 1181SO includes a standby

position on the range switch which maintains the polariz-

ing voltage on the sensor to enable faster response after

removal and replacement into the vessel.

SECTION 1.0

DESCRIPTION AND SPECIFICATIONS

• TWO-WIRE FIELD MOUNTED TRANSMITTERS. Ideal for multiple loop installations where

central data processing and control are required. Field mounting near the sensor for ease in

routine calibration.

• NEMA 4X WEATHERPROOF, CORROSION-RESISTANT, DUAL COMPARTMENT HOUSING

provides maximum circuit protection for increased reliability in industrial environments.

• HAZARDOUS AREA INSTALLATION. Certified NEMA 7B explosion-proof and intrinsically safe

when used with an approved sensor and safety barrier.

•

COMMONALITY OF PARTS reduces inventory required to support different field measurements.

• SWITCH SELECTABLE RANGES further reduces inventory by permitting calibration of one

Model to virtually any Tag Number requiring the same measurement.

• EXTERNAL ZERO AND SPAN, 20-turn potentiometers provide for fine calibration of the isolat-

ed 4-20 mA output signal.

MODEL 1181 SO SECTION 1.0

DESCRIPTION AN SPECIFICATIONS

1.2 SPECIFICATIONS

PHYSICAL SPECIFICATIONS – GENERAL

Enclosure: NEMA 4X, weatherproof and corrosion-

resistant

NEMA 7B, explosion proof

Hazardous Area Classification:

Explosion Proof (1181 PB & SO):

FM: Class I, Groups B, C, & D, Div. 1

Class II, Groups E, F, & G, Div. 1

Class III

CSA: Class I, Groups C & D

Class II, Groups E, F, & G

Class III, Encl 4

Class I, Groups A, B, C, & D, Div. 2

Encl 4, Factory Sealed

Intrinsic Safety (1181 PB & SO):

FM: Class I, II, III, Div. 1

CSA: Class I, Groups A, B, C & D, Encl 4

Temperature Code T4

CENELEC: Ex ia IIB T4 (Tamb = 55°C)

Display:

Analog: plug in, 90 degree, 2.5 inch diameter

1181PB: triple scale, 0-5, 0-10, 0-20 ppb X10

1181SO: triple scale, 0-100, 0-200, 0-800 mm Hg

Digital: 3.5 digit, LCD, adjustable range in engi-

neering units

Recommended Cable: Transmitter to Power Supply

Two Wire, 18 AWG, shielded, Belden 8760 or equal

(Rosemount Analytical P/N 9200001)

Weight/Shipping Weight:

Blind: 1.44 kg/1.89 kg (3.18 lbs/4.18 lbs)

Analog/Digital: 2.15 kg/2.6 kg (4.74 lb/5.75 lb)

PERFORMANCE SPECIFICATIONS – GENERAL

Power Supply Requirements:

(See Load/Supply Chart)

Lift Off Voltage:

Blind & Analog: 10 VDC

Digital: 12.5 VDC

Maximum Operating Power: 40 milliwatts

Output:

Blind & Analog: Isolated 4-20 mA into 700 ohms

at 24 VDC

Digital: Isolated 4-20 mA into 575 ohms at 24 VDC

Input/Output Isolation: 600 Volts

Ambient Temperature: –30° to 70°C

Relative Humidity: 0-90%

Digital Display Accuracy: 0.1% reading ±1.0 count

Analog Display Accuracy: ±2.0%

External Zero: ±7.0% full scale

External Span: ±7.0% full scale

Shock: 10G maximum for 10 milliseconds

Vibration: 0.025 inches double amplitude

5 to 50 Hz for 2 hours

EMI/RFI:

EN-61326

PERFORMANCE SPECIFICATIONS @ 25°C

Measurement Range: 0-100, 0-200, & 0-800 mm Hg

with Standby

Accuracy: ±1.0% full scale

Stability: ±0.1% full scale/month, non-cumulative

Repeatability: ±1.0 full scale

Temperature Coefficient: ±0.3 %/°C

Automatic Temperature Compensation: 15 to 50°C

RECOMMENDED SENSORS:

Model Hx438 Steam Sterilizable

Dissolved Oxygen Sensor

Model Gx448 Steam Sterilizable

Dissolved Oxygen Sensor

MODEL 1181 SO SECTION 1.0

DESCRIPTION AN SPECIFICATIONS

1.3 ORDERING INFORMATION

Model 1181 Two Wire Transmitter is housed in a NEMA 7B explosion-proof, 4X weatherproof, corrosion-resistant

enclosure and includes all the circuitry necessary for measurement and transmission of an isolated 4-20 mA signal.

The transmitter may be selected with local analog or digital display or as a blind unit.

Code Display (Required Selection)

02 Blind, no indication

03 Analog display

06 Digital display

Code Options (Order as separate line items)

07 ORDER AS P/N 2002577 Two-inch pipe/wall mounting bracket

11 ORDER AS P/N 9240594 Stainless steel nameplate (specify marking)

Code Agency Approvals

67 FM Explosion proof and Intrinsically Safe

69 CSA Explosion proof and Intrinsically Safe

73 CENELEC Intrinsically Safe/CE

Former Options

MODEL

1181SO TWO-WIRE TRANSMITTER

DIGITAL DISPLAY

LOAD/POWER SUPPLY REQUIREMENTS

+45 VDC @ 600 OHMS MIN. 1750 OHMS MAX.

12.5 VDC 24 VDC 35.5 VDC @ ZERO LOAD 45 VDC

LIFT OFF NOMINAL MAXIMUM

POWER SUPPLY VOLTAGE

1750 OHMS

@ 45 VDC

600 OHMS

@ 45 VDC

LOAD

RESISTANCE

REQUIRED

1.8 –

1.7 –

1.6 –

1.5 –

1.4 –

1.3 –

1.2 –

1.1 –

1.0 –

0.9 –

0.8 –

0.7 –

0.6 –

0.5 –

0.4 –

0.3 –

0.2 –

0.1 –

0.0 –

OPERATING

REGION

BLIND & ANALOG DISPLAY

LOAD/POWER SUPPLY REQUIREMENTS

+45 VDC @ 600 OHMS MIN. 1750 OHMS MAX.

10 VDC 24 VDC 33 VDC @ ZERO LOAD 45 VDC

LIFT OFF NOMINAL MAXIMUM

POWER SUPPLY VOLTAGE

1750 OHMS

@ 45 VDC

600 OHMS

@ 45 VDC

LOAD

RESISTANCE

REQUIRED

1.8 –

1.7 –

1.6 –

1.5 –

1.4 –

1.3 –

1.2 –

1.1 –

1.0 –

0.9 –

0.8 –

0.7 –

0.6 –

0.5 –

0.4 –

0.3 –

0.2 –

0.1 –

0.0 –

OPERATING

REGION

1181 SO 01 67 EXAMPLE

NOTE: Recommended cable from +24 volt DC power supply to Model 1181SO is Belden 8760 (PN 9200001); specify length.

MODEL 1181SO SECTION 2.0

INSTALLATION

SECTION 2.0

INSTALLATION

2.1 UNPACKING AND INSPECTION. Before opening

the shipping carton, inspect the outside of the carton

for any damage. If damage is detected, contact the

carrier immediately. If there is no apparent damage,

open the carton and inspect the instrument and hard-

ware. Make sure all the items in the packing list are

present and in good condition. Notify the factory if any

part is missing. If the instrument appears to be in sat-

isfactory condition, proceed to Section 2.2, Mechanical

Installation.

NOTE:

Save the original packing cartons and

materials as most carriers require

proof of damage due to mishandling,

etc., also, if it is necessary to return

the instrument to the factory, you must

pack the instrument in the same man-

ner as it was received (refer to Section

7.0 for return instructions).

2.2 MECHANICAL INSTALLATION.

IMPORTANT:

Do not attempt to install and operate

the 1181SO without first reading this

manual.

2.2.1 General. The transmitter may be installed in

harsh environments. However, it should be located in

an area where sources of temperature fluctuations,

vibrations, and shock are at a minimum or non exis-

tent. Pick a site that is at least 12 inches away from any

high voltage conduit and is easily accessed by operat-

ing and maintenance personnel.

2.2.2 Transmitter Installation. The 1181SO may be

mounted on a flat surface or on a 2-inch pipe by means

of a pipe mounting bracket (PN 2002577). There are

two threaded mounting holes located in the bottom of

the 1181SO housing (see Figure 2-1).

2.3 SENSOR INSTALLATION. Refer to the appropri-

ate Model Hx438 or Gx448 Sensor Instruction Manual

for proper installation. Do not install the sensor until the

calibration procedure is performed.

2.4 ELECTRICAL INSTALLATION.

2.4.1 Transmitter. Refer to Figure 2-2 for the wiring

details of the 1181SO. See Section 1.2 for the electri-

cal specifications.

The transmitter is equipped with two 1/2-inch conduit

openings, one on each side of the housing. One is for

power supply and signal wiring and the other is for

sensor input (see Figure 2-1).

To access the terminal boards, remove the cover on

the terminal (or meter) end of the transmitter, then

remove the meter assembly from the transmitter hous-

ing. The upper terminal block (TB1) is for the power

supply and meter connections. The lower terminal

block (TB2) is for the sensor input connections.

2.4.2 Wiring Procedure.

Connect the power wiring as follows:

+ VDC Power Supply to TB1-1

- VDC Power Supply to TB1-3

Connect the meter wiring as follows:

+ Meter Terminal to TB1-2

- Meter Terminal to TB1-3

Signal Wiring (4-20 mA DC output) is the same as for

power supply wiring:

+ Loop Signal to TB1-1

- Loop Signal to TB1-3

NOTE:

It is recommended that the power sup-

ply/signal wiring be twisted pairs

enclosed in a shielded cable. The

cable should be grounded in only one

place preferably at the instrument.

The instrument case shall be ground-

ed.

Signal or sensor wiring should never

be run in the same conduit or open

tray with AC power line, alarm, control

or output signal cables. Keep signal or

sensor wiring at least 12 inches from

heavy electrical equipment. (Note con-

tinued on page 6).

MODEL 1181SO SECTION 2.0

INSTALLATION

FIGURE 2-1 Mounting and Dimensional Drawing

MODEL 1181SO SECTION 2.0

INSTALLATION

NOTE CONT.

For maximum EMI/RFI protection the output

cable should be shielded and enclosed in an

earth grounded, rigid metal conduit. Connect

the output cable’s outer shield to the transmit-

ter’s earth ground via the ground terminal next

to TB-1.

The sensor cable should also be shielded.

Connect the sensor cable’s outer shield to the

transmitter’s earth ground via the ground ter-

minal next to TB1. If the sensor cable’s outer

shield is braided an appropriate metal cable

gland fitting may be used to connect the braid

to earth ground via the instrument case.

A new addition to the suite of tests done to

ensure CE compliance is IEC 1000-4-5. This is

a surge immunity test that simulates overvolt-

ages due to switching and lightning transients.

In order to meet the requirements of this test,

additional protection must be added to the

instrument in the form of a Transient Protector

such as the Rosemount Model 470D. This is a

3½-inch tube with ½-inch MNPT threads on

both ends. Inside the tube are gas discharge

and zener diode devices to limit surges to the

transmitter from the current loop. No addition-

al protection is needed on the sensor connec-

tions.

2.4.3 Sensor.

Carefully insert the spade lug terminated sensor cable

through the conduit opening. Connect the sensor to

TB2 as shown in Figure 2-2.

NOTE:

Conduit connections on the transmitter hous-

ing must be sealed or plugged (with a sealing

compound) to avoid accumulation of moisture

in the housing.

Please refer to the sensor's instruction manual

for additional information on its wiring.

IMPORTANT:

Make sure all wiring connections are correct

and tight. Do not apply power to the 1181SO at

this time.

For wiring to the Model Hx438 and Model Gx448

Dissolved Oxygen Sensors, please see Table 2-1.

2.5 HAZARDOUS LOCATIONS-EXPLOSION PROOF

INSTALLATION. In order to maintain the explosion

proof rating for installed transmitter, the following condi-

tions must be met:

1. The transmitter enclosure covers must be on hand

tight, and the threads must not be damaged

NOTE:

These covers seat on O-rings which

serve to provide a dust proof enclosure

for Class II and Class III installations.

2. Conduit must be properly installed with appropriate

seals.

3. If one of the conduit connections on the housing is

not used, it must be closed with a threaded metal

plug with at least five threads engaged.

4. The serial tag cover on the external ZERO and

SPAN adjustments must be in place.

5. FM Explosion proof installation must be in accor-

dance with Drawing Number 1400155 (See Figure

2-3).

6. Due to the nature of the measurement, sensors

cannot be designed to meet explosion proof certifi-

cation. If the sensors must be installed in haz-

ardous area locations, Rosemount Analytical Inc.

recommends that an intrinsically safe system be

installed.

2.6 HAZARDOUS LOCATIONS-INTRINSICALLY

SAFE INSTALLATION. To secure and maintain intrinsi-

cally safe installations for the appropriate approval

agency, the following conditions must be met:

1. Code 67 must be specified when ordering F.M. units.

Installation must be in accordance with Drawing Number

1400153 (Figure 2-4 Entity Approved Installation).

2. Code 69 must be specified when ordering CSA units and

installation must be performed in accordance with

Drawing Number 1400157 (Figure 2-5).

3. Code 73 must be specified when ordering CENELEC

units and installation must be performed in accordance

with Drawing Number 1400143 (Figure 2-6).

MODEL 1181SO SECTION 2.0

INSTALLATION

TABLE 2-1. Wiring Model 1181 SO Transmitter to

Model Hx438 and Gx448 DO Sensors

FIGURE 2-2. Model 1181 SO Wiring Details

TB2 MEASUREMENT WIRE COLOR

1 RTD IN Blue

2 RTD Sense Yellow

3 Cathode Clear

4 Anode Brown

Ground Yellow/green

MODEL 1181SO SECTION 2.0

INSTALLATION

FIGURE 2-3. FM Explosion-Proof Installation

DWG. NO. REV.

1400155 C

MODEL 1181SO SECTION 2.0

INSTALLATION

FIGURE 2-4. FM Intrinsically Safe Installation and Entity Parameters (1 of 3) [continued on following page]

MODEL 1181SO SECTION 2.0

INSTALLATION

FIGURE 2-4. FM Intrinsically Safe Installation and Entity Parameters (2 of 3) [continued on following page]

MODEL 1181SO SECTION 2.0

INSTALLATION

FIGURE 2-4. FM Intrinsically Safe Installation and Entity Parameters (3 of 3)

MODEL 1181SO SECTION 2.0

INSTALLATION

FIGURE 2-5. CSA Intrinsically Safe Installation

MODEL 1181SO SECTION 2.0

INSTALLATION

FIGURE 2-6. CENELEC Intrinsically Safe Installation (1 of 3) [continued on following page]

DWG. NO. REV.

1400143 C

MODEL 1181SO SECTION 2.0

INSTALLATION

FIGURE 2-6. CENELEC Intrinsically Safe Installation (2 of 3) [continued on following page]

DWG. NO. REV.

1400143 C

MODEL 1181SO SECTION 2.0

INSTALLATION

FIGURE 2-6. CENELEC Intrinsically Safe Installation (3 of 3)

DWG. NO. REV.

1400143 C

MODEL 1181SO SECTION 3.0

CONFIGURATION, START UP, AND CALIBRATION

SECTION 3.0

CONFIGURATION, START UP AND CALIBRATION

powered up with the range switch set to Stand-by even

when not in use. Setting the range switch to Stand-by

allows the sensor to be polarized while preparing for

calibration or while undergoing routine maintenance.

This also prevents the sensor from being oxygen sat-

urated. Sensor life will not be shortened under these

conditions because only a very small current flows

through the sensor. If for any reason the sensor has to

be disconnected (or the transmitter switched off) the

sensor will have to be repolarized before it can be

ready for further operation.

3.3.1 Sensor Current. During the polarization period,

the sensor (electrode) current will fall off even in oxy-

gen free solutions. For this reason, an excessive zero

current (sensor current at 0 mm Hg oxygen) may indi-

cate an incomplete polarization. Though the zero cur-

rent of the sensor is usually negligibly small and

almost identical with the 1181SO's zero point, the sen-

sor zero point should be checked periodically since an

excessive zero current may indicate a failing sensor

(refer to the Model Hx438 or Gx448 Sensor Manual for

additional information on sensor zero).

3.3.2 Zero Point Calibration. Prepare the calibration

set up as shown in Figure 3-1 (refer to the sensor's

instruction manual for additional information on zero

point calibration.

A. For low oxygen concentrations, or when the sensor

zero current exceeds 2-5% of full scale.

1. Follow Start up procedure (Section 3.3). Allow

three (3) hours for polarization period if the trans-

mitter was just powered up.

2. Set the range dip switches in their proper posi-

tions for the desired range.

3. Place the sensor in a freshly prepared, bubble

free, 2% bisulphite solution, or expose the sensor

in pure nitrogen gas. Let it stabilize.

4. When the reading is stable, adjust the external

zero pot to get a reading of 4 mA DC on M1.

3.1 GENERAL. This section provides the configura-

tion, start up and calibration procedures for the Model

1181SO Two-Wire Transmitter. The transmitter is used

in conjunction with the Rosemount Model Hx438 or

Gx448 Steam Sterilizable Dissolved Oxygen Sensor

and the Rosemount Model 515 Power Supply. (Refer

to Section 4.3 for 1181SO's Description of Controls.)

3.2 CONFIGURATION

3.2.1 1181SO with Analog Meter (Option-03). The

desired range may be selected by placing the Range

Dip Switches in their proper positions. The analog

meter has a scale with three different ranges of 0-100

mm Hg, 0-200 mm Hg, and 0-800 mm Hg. The analog

meter is proportionally activated by the transmitter's 4-

20 mA output. The oxygen concentration is obtained

by reading the position of the needle on the pre-select-

ed range on the meter face.

NOTE:

A special meter face may be ordered

to read in your desired scale units.

Consult the factory.

3.2.2 1181SO with LCD (Option-06). The LCD Meter

has its own zero and span adjustment pots for further

calibration. The 1181SO with LCD meter (Option-06)

may be configured to read directly in mm Hg, mg/l or

ppm, % O

or % saturation (see Table 3-1) for various

ranges and units and their corresponding range dip

switch positions).

3.3 START UP. Start up the 1181SO by performing the

following procedures:

1. Make sure the 1181SO is properly wired. (refer to

Figure 2-2)

2. Power up the 1181SO.

3. Set the range dip switches to "STBY" (Stand-by).

When the transmitter is powered up, a polarization

voltage is applied between the anode and the cathode.

The sensor (electrode) current is initially very high then

it falls off quickly and settles down to a steady state

after a few hours. Since this polarization period is rela-

tively long, it is recommended to leave the 1181SO

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Rosemount 1181-SO Dissolved Oxygen Transmitter Owner's manual

Brand: Rosemount

Model: 1181-SO Dissolved Oxygen Transmitter

Category: Oxygen Equipment

Type: Owner's manual

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Rosemount 1181-SO Dissolved Oxygen Transmitter Owner's manual

Rosemount 1181-SO Dissolved Oxygen Transmitter Owner's manual

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