In-situ RDO PRO-X User manual

Operator's Manual
RDO®PRO-X Process Optical Dissolved Oxygen Probe
Information subject to change without notice. In-Situ, In-Situ logo, Baro Merge, BaroTROLL, HERMIT, HydroVu™, iSitu, Pocket-Situ, RDO,
RuggedCable, RuggedReader, SmarTROLL™, TROLL, VuSitu, and Win-Situ are trademarks or registered trademarks of In-Situ Inc.©2008-
2015. All rights reserved. This product may be covered by patents identified at www.in-situ.com/patents
0090102 | 2019-05-10

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Copyright © 2008-2015 by In-Situ All rights reserved.
This document contains proprietary information which is protected by copyright. No part of this document may be
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In-Situ makes no warranty of any kind with regard to this material, including, but not limited to, its fitness for a particular
application. In-Situ will not be liable for errors contained herein or for incidental or consequential damages in connection with
the furnishing, performance, or use of this material.
In no event shall In-Situ Inc. be liable for any claim for direct, incidental, or consequential damages arising out of, or in
connection with, the sale, manufacture, delivery, or use of any product.
In-Situ and the In-Situ logo, Win-Situ, TROLL, Baro Merge, BaroTROLL, HERMIT, HyroVu™, iSitu, Pocket-Situ, RDO,
RuggedCable, RuggedReader, TROLL, and VuSitu™, Win-Situ are trademarks or registered trademarks of In-Situ Inc.
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The presence of the Waste Electrical and Electronic Equipment (WEEE) marking
on the product indicates that the device is not to be disposed via the
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Union.
For products under the requirement of WEEE directive, please contact your
distributor for the proper decontamination information and take back
program, which will facilitate the proper collection, treatment, recovery,
recycling, and safe disposal of the device.

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Table of Contents
1 Optical RDO PRO-X Dissolved Oxygen Probe Specifications 5
2 Introduction 6
System Description 6
Serial Numbers 7
Unpack the Probe 7
3 Calibrate the RDO PRO-X Probe 9
1-Point Calibration 9
Water-Saturated Air 9
2-Point Calibration 9
100% and 0% Saturation 9
4 Probe Deployment 11
5 Care and Maintenance 12
Clean the Sensor Cap 12
Clean the Optical Window 12
Clean the Probe 12
Sensor Cap Storage 12
Replace the Sensor Cap 12
Maintain Desiccant 13
6 Controller Requirements and Connections 14
Wiring Overview 14
Analog (4-20 mA) 3-wire 15
SDI-12 (3-wire) 16
Modbus Master with Built-in RS485 17
Modbus Master with Built-in RS232 (Converter Required) 18
Converter 19
Power Connections 19
Communications 19
7 Modbus Registers 20
Common Registers 20
Sensor Status Registers 20
Device Specific Register 0042 Data Quality ID 20
Device Specific Registers 21
8 Dissolved Oxygen Equations 22
Dissolved Oxygen Concentration 22
Dissolved Oxygen, % Saturation 23
9 Calibration Registers 24
Live Salinity Value 24
Default Salinity Value 24
Live Barometric Pressure 24
Default Barometric Pressure 24

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100% Saturation Calibration Values 24
0% Saturation Calibration Values 24
Calibration Slope and Offset 25
Entering Calibration Registers 25
Calibration Calculations 26
10 Service 27
Sensor Health Table 27
11 Appendix A - Communication Device 28
Install and Open the Software 28
Connect the Probe to the Communication Device 28
12 Declaration of Similarity 29

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Optical RDO PRO-X Dissolved Oxygen Probe Specifications
Optical RDO PRO-X Dissolved Oxygen Probe
Sensor Type Optical (luminescent) dissolved oxygen sensor
RDO PRO-X Probe
Range: 0 to 60 mg/L concentration
Accuracy: ±0.1 mg/L from 0 to 20 mg/L
±2% of reading from 20-60 mg/L
Resolution: 0.01 mg/L
Response time: T90 < 45 sec; T95 < 60 sec @ 25°C
Storage conditions: -5° to 60° C (23° to 140° F)
RDOClassic Cap
RDO-X Sensor Cap
RDOFast Cap
Usage life: 2 years typical
Storage conditions: 1° to 60° C (33° to 140° F), in factory container
Temperature sensor
Range: 0° to 50° C (32° to 122° F)
Accuracy: ±0.1° C typical
Resolution: 0.01° C
Transmitter/local display Optional, or use with Con TROLL PRO System
Communications options Modbus/RS485, 4-20 mA, SDI-12
Max. power consumption 50 mA at 12 VDC
Measure current 6 mA typical at 24 VDC
Idle current (no measurement or
communication) 160 µA typical at 24 VDC
Maximum cable length Up to 1,219 m (4,000 ft) (for Modbus and 4-20 mA) or up to 60.96 (200 ft) for SDI-12
Cable options 10 m fixed stripped-and-tinned; Twist-lock connector with user-selectable cable
length
Internal mounting thread 1¼ - 11 ½ NPT
IP rating IP-67 with cap off, IP-68 with cap installed
Compliance Heavy industrial, IEC 61000-6-2:2005
Salinity compensation Fixed or real-time capable (using controller)
Barometric pressure Fixed or real-time capable (using controller)
Maximum pressure 150 psi from 0 to 50° C; 300 psi @ 25° C
Warranty Probe: 3 years from date of shipment
RDO-X Sensor Cap: 2 years in typical applications
Methods Standard Methods 4500-O; In-Situ Methods 1002-8-2009,1003-8-2009, 1004-8-2009
(EPA approved)

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Introduction
The RDO PRO-X Probe is a rugged, reliable instrument designed to deliver accurate dissolved oxygen (DO) data across a
wide measurement range and to reduce maintenance costs. The probe features the latest optical technology for DO
measurement.
System Description
The RDO PRO-X system consists of the following items.
lBlack probe body with removable nose cone
lOptical RDO-X Sensor Cap, Classic Cap, or Fast Cap
lTitanium thermistor
RuggedCable System
l10-m standard length with stripped-and-tinned ends
lCustomized lengths with titanium twist-lock connectors
1 Cable end, stripped-and-tinned
2 Nose cone
3 RDO-X Sensor Cap
4 Thermistor

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1 Probe
2 Cable end, twist-lock connector and RuggedCable System
Serial Numbers
The probe serial number is engraved on the side of the unit. The cap serial number is programmed on the memory chip inside
the cap.
Unpack the Probe
1. Remove the probe from the box and other packaging materials.
2. Unscrew the nose cone from the probe and remove the red protective dust cap from the sensor. Save the dust cap
for later use.
1 Dust cap
2 Nose cone
3. Remove the RDO cap from the storage sleeve.
4. Align the arrow on the cap with the index mark on the probe and firmly press the cap onto the probe, without
twisting, until it seals over the probe body.

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1 Alignment arrow on cap
2 Cap installed over lens
3 Nose cone
Do not allow moisture or atmospheric humidity inside the cap. Keep the cap in its sealed
package until you are ready to install it. Install promptly. Ensure that O-ring grooves are dry and
that the O-ring is not rolled or pinched inside the cap.
The typical cap lifetime is two years after the first reading has been taken.
5. Reattach the nose cone.

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Calibrate the RDO PRO-X Probe
Calibrate the sensor with Win-Situ 5 software or the VuSitu mobile app, or calibrate directly with your controller.
1-Point Calibration
The optical Rugged Dissolved Oxygen sensor is very stable. The factory calibration should produce readings within 3%
accuracy. If you require readings with greater accuracy we recommend that you perform a 1-point, 100% water-saturated air
calibration as described below.
Water-Saturated Air
1. Remove the storage cap from the top of the calibration chamber and replace it with the vented calibration cap.
1 Storage cap
2 Vented calibration cap
Figure 6.1 Storage cap and vented calibration cap shown together
2. Place the sponge wafer in the bottom of the calibration chamber and saturate with approximately 10 mL water.
3. Gently dry the instrument and sensing material with a paper towel, making sure there is no water or debris on the
instrument or on the sensing surface.
4. Place the instrument into the calibration chamber about 2.5 cm (1 in.) above the water-saturated sponge.
Figure 6.2 Calibration chamber with water-saturated sponge
5. Allow 5 to 10 minutes for temperature stabilization prior to starting the calibration procedure. Do not leave the
instrument in the calibration chamber for more than 30 minutes. This can allow condensation to form on the
sensing material, which will produce false low readings after calibration. If condensation does occur, remove the
instrument, dry the sensing material, place the instrument in the chamber, and calibrate.
2-Point Calibration
100% and 0% Saturation
We recommend that you perform the 0 % oxygen calibration only if you intend to measure dissolved oxygen at a
concentration of less than 4 mg/L.

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1. Set up the calibration procedure as previously described, and perform a water-saturated air calibration.
2. Remove the water-saturated sponge from the calibration chamber and fill the chamber to the fill line with
approximately 60 mL of fresh sodium sulfite solution.
1 Fill line
2 Temperature sensor
2. Place the instrument into the solution. Leave at least 13 mm (0.5 in.) between the surface of the sensing material
and the bottom of the chamber.
3. Ensure that the temperature sensor is completely submerged in the solution.
4. Allow at least 5 minutes for the temperature to stabilize prior to performing the calibration procedure.
5. Once calibration is complete, remove the sensor, and thoroughly rinse to remove all of the sodium sulfite.

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Probe Deployment
The cable end of the RDO PRO-X Probe is internally threaded (1¼ – 11½ NPT) and can be attached to a male threaded pipe.
When deployed, make sure that the nose cone and thermistor are completely submerged.
1 10 m cable attached
2 Twist-lock connector
3 1 1/4 NPT threading

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Care and Maintenance
Clean the Sensor Cap
1. The cap and nose cone must remain on the probe.
2. Rinse the sensor with clean water from a squirt bottle or spray bottle.
3. Gently wipe with a soft-bristled brush or soft cloth if biofouling is present. Use Alconox to remove grease.
4. If extensive fouling or mineral build-up is present, soak the cap end in vinegar for 15 minutes, then soak in
deionized (DI) water for 15 minutes.
Do not use organic solvents—they will damage the sensing element. Do not remove the cap
from the sensor prior to cleaning.
5. After cleaning, perform a 1- or 2-point user calibration or calibration check.
Clean the Optical Window
1. Clean the optical window only when you change the cap. See full instructions in the sensor cap replacement kit.
2. Remove the cap and gently wipe the lens with the supplied lens cloth.
Do not wet the lens area with water or any solution. Use only the supplied lens cloth for
cleaning. Do not use any other cloth or material.
Clean the Probe
With the RDO cap installed on probe, gently scrub the probe with a soft-bristled brush or nylon dish scrubber. Use Alconox to
remove grease or other matter. Soak in vinegar and DI water to remove mineral deposits or extensive fouling.
Sensor Cap Storage
Prior to installation—Store in factory supplied container.
Installed—Store in the calibration chamber with the storage cap attached and a few drops of clean water.
Replace the Sensor Cap
1. Remove the probe nose cone.
2. Use a lint-free cloth to remove any moisture from the probe.
3. Pull the used RDO cap off of the sensor, without twisting.
4. Remove the existing O-rings from the sensor.
Ensure that there is no moisture in the O-ring grooves. Do not touch or clean the lens with
anything other than the supplied lens wipe.
5. Use your finger to apply a very light layer of silicone-based lubricant around the O-ring grooves.
6. Place the O-rings on the sensor. Apply another thin layer of lubricant to the O-rings and grooves.
Note: Do not transfer grease to the lens or sensor pins.
7. Clean the sensor lens with the wipe provided in the kit and allow it to thoroughly dry. Inspect for scratches or dirt.

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8. Remove the new cap from its sealed packaging and attach it to the sensor, being careful to press firmly, without
twisting, until it seals over the lens. Make sure that the O-rings are not pinched or rolled between the cap and
sensor.
9. Replace the nose cone.
10. Perform a 1- or 2-point calibration.
Maintain Desiccant
Desiccant installed in a controller or transceiver protects probe electronics from condensation. A desiccant pack changes
color from blue to pink as it becomes saturated with moisture.
It is extremely important to use the proper size desiccant for your deployment and to
change desiccant often. Desiccant should be changed before the entire pack has turned
pink, and you should use enough to effectively keep cables and probes dry until your next
scheduled maintenance. Desiccant lifespan is dependent on site conditions.

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Controller Requirements and Connections
The RDO PRO-X Probe may be connected to a controller or logger for communication via the following options.
lAnalog (4-20 mA) provides a configurable 4-20 mA current loop output
lSDI-12
lRS485 Modbus
lRS232 to Modbus
Wiring Overview
Refer to diagrams on the following pages. Trim and insulate unused wires. The shielded wire should be connected to a
chassis ground or earth ground.
The inside of the controller must be kept free of moisture and humidity. Condensed
moisture can migrate through the wiring and cause the probe to fail. Therefore, desiccant
should be installed in the controller and be replaced on a regular basis.

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Analog (4-20 mA) 3-wire
Signal Color
Ground/Return Black
External Power (12-36
VDC) Red
4-20 mA Brown
Cable length must not exceed 1219 m (4000 ft.)
Analog signal must be enabled in Win-Situ 5 Software or the Comm Kit Software prior to
use.

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SDI-12 (3-wire)
Signal Color
Ground/Return Black
External Power (9.6-16
VDC) Red
RS485 (-) Green
RS485 (+) Blue
SDI-12 White
Cable length must not exceed 60.96 m (200 ft.)

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Modbus Master with Built-in RS485
Signal Color
Ground/Return Black
External Power
(12-36 VDC) Red
RS485 (-) Green
RS485 (+) Blue
Cable length must not exceed 1219 m (4000 ft.)

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Modbus Master with Built-in RS232 (Converter Required)
Signal Color
Ground/Return Black
External Power
(12 VDC, voltage limited by converter) Red
RS485 (-) Green
RS485 (+) Blue
Cable between converter and master must not exceed 60.96 m (20 ft.)
Cable between master and slave must not exceed
1219 m (4000 ft.)

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Converter
Power Connections
The red wire provides power for all system modes. Analog output is disabled by default. However, the 4-20 mA current loop
output can be continuous in Modbus or SDI-12 mode as long as Modbus device register 9507 is set to 1.
Communications
The device automatically switches between Modbus and SDI-12 modes depending on which of the two interfaces has
activity. Modbus and SDI-12 cannot be used at the same time—whichever one is currently in use will block communication
on the other.

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Modbus Registers
Common Registers
Register Size
Mode &
Access Level
(R/W)
Data Type Description
9001 1 R/W ushort Device ID = 19 for RDO Titan31 for RDO PRO-X35 for
RDOBlue
9002 2 R/W ulong Device serial number
9004 3 R/W time Manufacture date
Sensor Status Registers
Register Size
Mode &
Access Level
(R/W)
Data Type Description
0005 3 R1 time Cap start date/time
0 = no cap
0008 3 R1 time Cap end of usable life date/time
0 = no cap
Device Specific Register 0042 Data Quality ID
Register 0042 is responsible for returning the various data quality IDs for the RDO sensor. For a list of the Data Quality IDs
and definitions, see the Sensor Health Table in the Service and Troubleshooting section of this manual.