Campbell CS511 User manual

Revision: 03/2022
Copyright © 2001– 2022
Campbell Scientific, Inc.

Table of contents
1. Introduction 1
2. Precautions 1
3. Initial inspection 1
4. QuickStart 2
5. Overview 4
6. Specifications 5
7. Installation 6
7.1 Getting sensor ready to use 7
7.2 Wiring 8
7.3 Programming 8
7.4 Calibration 9
8. Maintenance 10
Appendix A. Importing Short Cut code into CRBasic Editor 13
Appendix B. Example program 14
Appendix C. Dissolved oxygen tables 16
Table of Contents - i

1. Introduction
The CS511 is a rugged, low-maintenance sensor that is manufactured by Sensorex. It consists of a
self-polarizing galvanic cell that generates a millivolt signal proportional to the amount of
oxygen present in the measured medium (typically water).
NOTE:
This manual provides information only for CRBasic data loggers. For retired Edlog data logger
support, see an older manual at www.campbellsci.com/old-manuals . Also refer to an older
manual if the CS511 was purchased before June 2008 and for information on using the retired
PT4-L Agitator.
2. Precautions
lREAD AND UNDERSTAND the Safety section at the back of this manual.
lThe CS511 is a precision instrument. Please handle it with care.
lBecause the CS511 is shipped dry, electrolyte needs to be added before using the sensor.
See Getting sensor ready to use (p. 7) for more information.
lLetting the CS511 dry in the field shortens the life of the membrane and sensor.
lThe sensor should be stored dry and empty. Therefore, empty the electrolyte, rinse the
sensor, and remove the membrane.
lReplace the membrane and recalibrate the sensor before redeploying the CS511 after it has
been stored out of water or dried up in the field.
lWhile cleaning, do not touch the center electrode. See Maintenance (p. 10) for more
information.
3. Initial inspection
lUpon receipt of the CS511 inspect the packaging and contents for damage. File damage
claims with the shipping company.
CS511 Dissolved Oxygen Sensor 1

lImmediately check package contents against the shipping documentation. Contact
Campbell Scientific about any discrepancies.
lThe model number and cable length are printed on a label at the connection end of the
cable. Check this information against the shipping documents to ensure the expected
product and cable length were received.
4. QuickStart
A video that describes data logger programming using Short Cut is available at:
www.campbellsci.com/videos/cr1000x-data logger-getting-started-program-part-3 .Short
Cut is an easy way to program your data logger to measure the sensor and assign data logger
wiring terminals. Short Cut is available as a download on www.campbellsci.com . It is included
in installations of LoggerNet,RTDAQ, and PC400.
The following procedure also shows using Short Cut to program the CS511.
1. Open Short Cut and click Create New Program.
2. Double-click the data logger model.
3. In the Available Sensors and Devices box, type CS511 or locate the sensor in the Sensors >
Water >Quality folder. Double click on the CS511 Dissolved Oxygen Probe. The default
calibration value of 0.34 is based on an average. It is preferable to calibrate the sensor by
using the procedure provided in Calibration (p. 9).
CS511 Dissolved Oxygen Sensor 2

4. Click on the Wiring tab to see how the sensor is to be wired to the data logger. Click OK
after wiring the sensor.
5. In Output Setup, type the scan rate, meaningful table names, and Data Output Storage
Interval. Click Next.
CS511 Dissolved Oxygen Sensor 3

6. Select the measurement and its associated output option.
7. Click Finish and save the program. Send the program to the data logger if the data logger
is connected to the computer.
8. If the sensor is connected to the data logger, check the output of the sensor in the data
display in LoggerNet,RTDAQ, or PC400 to make sure it is making reasonable
measurements.
5. Overview
The CS511 is a galvanic sensor, which produces a millivolt signal proportional to the amount of
oxygen present in the measured medium. Oxygen diffuses through the membrane onto the
cathode, reacts chemically, and combines with the anode. An electrical current is produced by
this chemical reaction which is converted from microamps to millivolts by an in-line resistor. An
in-line thermistor also conditions the signal providing automatic temperature compensation.
With these features, the sensor produces a linear, millivolt output proportional to the oxygen
present in the medium in which it is placed.
The sensor consists of two parts, an upper part with cathode, anode, and cable, and a lower part
comprising of a screw-on membrane cap. The CS511 is shipped dry, but has a membrane
installed in the cap. With the membrane in place, the cap must be filled with electrolyte solution
before the cap is screwed onto the top component.
The CS511 is self-polarizing and requires no external power source.
CS511 Dissolved Oxygen Sensor 4

Features:
lIn-line thermistor provides automatic temperature compensation
lCompatible with Campbell Scientific CRBasic data loggers: CR6, CR1000X, CR800-series,
CR350-series, CR300-series, CR3000, CR1000
6. Specifications
Principle of measurement: Membrane-covered, galvanic oxygen sensor
Output signal: 33 mV ± 9 mV (100% saturation), < 2 mV (0% saturation)
Measurement range: 0.5 to 50 ppm
Accuracy: Better than ± 2% of reading ± 1 digit when calibration
temperature equals measuring temperature ± 5 °C
Response time: 5 min. from 100% to 0% oxygen
Operating conditions
Temperature: 0 to 50 °C (32 to 122 °F)
Pressure: 0 to 100 psig
Minimum submersion depth: 60 mm (2.5 in)
Minimum water flow: 5 cm/s (2 in/s) across membrane
Calibration: In air or in air saturated water
Temperature compensation: Automatic from 4 to 40 °C (40 to 104 °F)
Sensor electrolyte: NaCl + glycerol (prevents freezing)
Materials
Body: Noryl
Anode: Zinc
Cathode: Silver
Cable jacket: PVC
Diameter: 5.72 cm (2.25 in)
Height: 17.78 cm (7 in) from bottom of sensor to end of cable-strain
relief; see Figure 6-1 (p. 6)
Shipping weight: 0.8 kg (1.75 lb) including sensor and shipping kit
CS511 Dissolved Oxygen Sensor 5

Figure 6-1. CS511 dimensions
7. Installation
If you are programming your data logger with Short Cut, skip Wiring (p. 8) and Programming (p.
8). Short Cut does this work for you. See QuickStart (p. 2) for a Short Cut tutorial.
CS511 Dissolved Oxygen Sensor 6

7.1 Getting sensor ready to use
1. Unscrew the lower body from the upper body.
Figure 7-1. Separate the lower body from the upper body
2. Inspect the membrane for wrinkles. Replace membrane if wrinkled. See Maintenance(p.10).
3. Pour clean water into the lower body and look for leakage around the membrane. Dispose
of the water, and if there is leakage, replace membrane. See Maintenance(p.10).
Figure 7-2. Check for leakage
CS511 Dissolved Oxygen Sensor 7

4. Pour fresh electrolyte in the bottom cap and fill to the top of the cap.
5. Keep the sensor upright with the cable pointed upwards (not sideways). Screw the bottom
cap onto the upper body until hand tight.
7.2 Wiring
Data logger connection is provided in following table. The CS511 can use one differential terminal
or one single-ended terminal. Differential wiring is better at rejecting electrical noise and ground
loop error.
Table 7-1: Wire color, function, and data logger connections
Wire
color Wire function Differential data logger connection
Single-ended
data logger connection
White Signal high
Uconfigured for differential
input1,DIFF H (differential high,
analog-voltage input)
Uconfigured for single-ended
input1,SE (single-ended, analog-
voltage input)
Black Signal reference
Uconfigured for differential
input1,DIFF L (differential low,
analog-voltage input)
⏚(analog ground)
Clear Shield ⏚(analog ground) ⏚(analog ground)
1Uterminals are automatically configured by the measurement instruction.
7.3 Programming
Short Cut is the best source for up-to-date programming code for Campbell Scientific data
loggers. If your data acquisition requirements are simple, you can probably create and maintain a
data logger program exclusively with Short Cut. If your data acquisition needs are more complex,
the files that Short Cut creates are a great source for programming code to start a new program
or add to an existing custom program.
NOTE:
Short Cut cannot edit programs after they are imported and edited in CRBasic Editor.
AShort Cut tutorial is available in QuickStart (p. 2). If you wish to import Short Cut code into
CRBasic Editor to create or add to a customized program, follow the procedure in Importing
Short Cut code into CRBasic Editor (p. 13). This document provides programming basics for
CRBasic data loggers. A complete program is provided in Example program (p. 14).
CS511 Dissolved Oxygen Sensor 8

The VoltDiff() or VoltSE() can be used to measure the CS511. Choose a voltage range of
100mV or higher. Refer to the following section for information on determining the multiplier.
7.4 Calibration
The multiplier is used to calibrate the CS511 sensor. Do the following to calculate the multiplier:
1. Program the data logger by using a multiplier of one; see QuickStart (p. 2) or Programming
(p. 8).
2. Connect the CS511 to the data logger.
3. If the CS511 has been deployed in the field, gently wipe the membrane with a soft cloth.
4. Place the CS511 in air away from direct sunlight with the membrane facing upward.
5. Place a drop of clean water on the membrane.
6. Wait for readings to stabilize. This may take 15 minutes or more.
7. Determine the air temperature and barometric pressure.
8. Using a calibration chart such as that provided in Dissolved oxygen tables (p. 16), determine
the oxygen concentration of the air.
9. Use the following equation to calculate the multiplier:
M = P/R
where: M = Multiplier
P = Concentration in PPM of the air (from the calibration chart)
R = The signal output of the sensor when using a multiplier of one
10. Change the multiplier in the data logger program from one to the calculated number; see
QuickStart (p. 2) or Programming (p. 8).
Instead of step 10, the following expression can be used that allows a new multiplier to be added
to the program without rewriting, compiling, and downloading the program to the data logger.
DOppm = DOMult * DOmV
With this method, the multiplier value is typed into the expression through the Public Table by
using the numeric display in LoggerNet,PC400, or data logger keyboard display.
CS511 Dissolved Oxygen Sensor 9

8. Maintenance
Campbell Scientific offers maintenance kits that contain membranes, membrane O-rings,
washers, and a bottle of electrolyte. A spare parts kit is also available that contains two
membrane locks, two tensioning washers, two body O-rings, and one membrane replacement
tool. Refer to www.campbellsci.com/order/cs511-l for more information.
The CS511 uses a strong, easy-to-clean, and easy-to-change membrane in a screw-on membrane
cap. The sensor can be fully overhauled in five minutes.
Cleaning sensor and replacing membrane procedure:
1. Unscrew the lower body from the upper body. See Figure 7-1 (p. 7).
2. Safely dispose of the electrolyte.
CAUTION:
Make sure the O-ring does not fall out of the cap.
3. Using the membrane tool, unscrew the membrane lock that is in the lower body; see Figure
8-1 (p. 10).
4. Remove and dispose of the membrane and its O-ring.
Figure 8-1. Remove membrane and membrane O-ring
CS511 Dissolved Oxygen Sensor 10

5. To clean, immerse the top part of the sensor in distilled white vinegar (3% acetic acid) for
about 30 minutes. If vinegar is unavailable, use a soft toothbrush, automatic dishwasher
detergent, and clean water to clean the cathode, anode, and plastic without touching the
center electrode; see Figure 8-2 (p. 11). Rinse all components thoroughly with clean water
after cleaning.
CAUTION:
Avoid touching or scratching the center electrode while cleaning.
Figure 8-2. Using toothbrush to clean sensor
6. Replace the membrane and its O-ring. See Figure 8-3 (p. 12)
a. Place the new O-ring at the bottom of the membrane cavity.
b. Remove the paper backing from a new membrane.
c. Place the new membrane on top of the O-ring.
d. Place the washer on top of the membrane.
e. Using the membrane tool, install the membrane lock on top of the washer.
CAUTION:
Make sure the cap is upright (not sideways) when securing the membrane lock to
the washer.
CS511 Dissolved Oxygen Sensor 11

Figure 8-3. Proper O-ring placement
7. Inspect the membrane for wrinkles. Replace membrane if wrinkled.
8. Pour clean water into the lower body and look for leakage around the membrane. Dispose
of the water, and if there is leakage, replace membrane. See Figure 7-2 (p. 7).
9. Pour fresh electrolyte in the bottom cap and fill to the top of the cap.
10. Keep the sensor upright with the cable pointed upwards (not sideways). Screw the bottom
cap onto the upper body until hand tight.
NOTE:
Excess electrolyte will leak out at the joint between the sensor cap and upper body.
CS511 Dissolved Oxygen Sensor 12

Appendix A. Importing Short
Cut code into CRBasic Editor
Short Cut creates a .DEF file that contains wiring information and a program file that can be
imported into the CRBasic Editor. By default, these files reside in the C:\campbellsci\SCWin folder.
Import Short Cut program file and wiring information into CRBasic Editor:
1. Create the Short Cut program. After saving the Short Cut program, click the Advanced tab
then the CRBasic Editor button. A program file with a generic name will open in CRBasic.
Provide a meaningful name and save the CRBasic program. This program can now be
edited for additional refinement.
NOTE:
Once the file is edited with CRBasic Editor,Short Cut can no longer be used to edit the
program it created.
2. To add the Short Cut wiring information into the new CRBasic program, open the .DEF file
located in the C:\campbellsci\SCWin folder, and copy the wiring information, which is at
the beginning of the .DEF file.
3. Go into the CRBasic program and paste the wiring information into it.
4. In the CRBasic program, highlight the wiring information, right-click, and select Comment
Block. This adds an apostrophe (') to the beginning of each of the highlighted lines, which
instructs the data logger compiler to ignore those lines when compiling. The Comment
Block feature is demonstrated at about 5:10 in the CRBasic | Features video .
CS511 Dissolved Oxygen Sensor 13

Appendix B. Example program
This CR1000X program measures the sensor using the VoltDiff() instruction. Other CRBasic
data loggers are programmed similarly. The following table shows the wiring for the example.
Table B-1: Wiring for CR1000X example
CR1000X connection Sensor wire color
1H White
1L Black
⏚Clear
CRBasic Example 1: CR1000X program that measures the CS511 using the VoltDiff() instruction
'CR1000X
'Declare Variables and Units
Public Batt_Volt
Public DOmV
Public DOppm
Public DOMult
Units Batt_Volt=Volts
Units DOmV=mV
Units DOppm=ppm
'Define Data Tables
DataTable(Hourly,True,-1)
DataInterval(0,60,Min,10)
Sample(1,DOmV,FP2) Sample(1,DOppm,FP2)
Sample(1,Batt_Volt,FP2)
EndTable
DataTable(Daily,True,-1)
DataInterval(0,1440,Min,10)
Minimum(1,Batt_Volt,FP2,False,False)
EndTable
'Main Program
BeginProg
Scan(5,Sec,1,0)
CS511 Dissolved Oxygen Sensor 14

CRBasic Example 1: CR1000X program that measures the CS511 using the VoltDiff() instruction
'Default Data logger Battery Voltage measurement Batt_Volt:
Battery(Batt_Volt)
'CS511 Dissolved Oxygen Sensor measurements DOmV and DOppm:
VoltDiff(DOmV,1,mV200,1,True,0,60,1,0)
DOppm = DOMult * DOmV
'Call Data Tables and Store Data
CallTable(Hourly)
CallTable(Daily)
NextScan
EndProg
CS511 Dissolved Oxygen Sensor 15

Appendix C. Dissolved oxygen
tables
Table C-1 (p. 16) is a dissolved oxygen table for fresh water applications and Table C-2 (p. 18) is a
dissolved oxygen table for salt water applications.
Table C-1: Dissolved oxygen solubility (mg/L) as a function of temperature
and elevation for moist air
Temp.
(° C)
Elevation above sea level
0 m
(0 ft)
152 m
(500 ft)
305 m
(1000 ft)
457 m
(1500 ft)
610 m
(2000 ft)
762 m
(2500 ft)
914 m
(3000 ft)
1067 m
(3500 ft)
1219 m
(4000 ft)
1372 m
(4500 ft)
1524 m
(5000 ft)
1676 m
(5500 ft)
1829 m
(6000 ft)
0 14.6 14.34 14.09 13.84 13.6 13.36 13.12 12.89 12.67 12.44 12.22 12.01 11.8
1 14.2 13.95 13.7 13.46 13.22 12.99 12.76 12.54 12.32 12.1 11.89 11.68 11.47
2 13.81 13.57 13.33 13.1 12.87 12.64 12.42 12.20 11.98 11.77 11.56 11.36 11.16
3 13.45 13.21 12.98 12.75 12.52 12.3 12.09 11.87 11.66 11.46 11.26 11.06 10.86
4 13.09 12.86 12.64 12.41 12.2 11.98 11.77 11.56 11.36 11.16 10.96 10.77 10.58
5 12.76 12.53 12.31 12.09 11.88 11.67 11.47 11.26 11.07 10.87 10.68 10.49 10.31
6 12.44 12.22 12 11.79 11.58 11.38 11.18 10.98 10.79 10.6 10.41 10.23 10.05
7 12.13 11.91 11.7 11.5 11.29 11.1 10.9 10.71 10.52 10.33 10.15 9.97 9.8
8 11.83 11.62 11.42 11.22 11.02 10.83 10.63 10.45 10.26 10.08 9.91 9.73 9.56
9 11.55 11.34 11.15 10.95 10.76 10.57 10.38 10.2 10.02 9.84 9.67 9.5 9.33
10 11.28 11.08 10.88 10.69 10.5 10.32 10.14 9.96 9.78 8.61 9.44 9.27 9.11
11 11.02 10.82 10.63 10.44 10.26 10.08 9.9 9.73 9.56 9.39 9.22 9.06 8.9
12 10.77 10.58 10.39 10.21 10.03 9.85 9.68 9.51 9.34 9.17 9.01 8.85 8.7
13 10.53 10.34 10.16 9.98 9.8 9.63 9.46 9.29 9.13 8.97 8.81 8.66 8.5
14 10.29 10.11 9.93 9.76 9.59 9.42 9.25 9.09 8.93 8.77 8.62 8.47 8.32
15 10.07 9.89 9.72 9.55 9.38 9.22 9.05 8.89 8.74 8.58 8.43 8.28 8.14
16 9.86 9.68 9.51 9.35 9.18 9.02 8.86 8.7 8.55 8.4 8.25 8.11 7.96
CS511 Dissolved Oxygen Sensor 16

Table C-1: Dissolved oxygen solubility (mg/L) as a function of temperature
and elevation for moist air
Temp.
(° C)
Elevation above sea level
0 m
(0 ft)
152 m
(500 ft)
305 m
(1000 ft)
457 m
(1500 ft)
610 m
(2000 ft)
762 m
(2500 ft)
914 m
(3000 ft)
1067 m
(3500 ft)
1219 m
(4000 ft)
1372 m
(4500 ft)
1524 m
(5000 ft)
1676 m
(5500 ft)
1829 m
(6000 ft)
17 9.65 9.48 9.31 9.15 8.99 8.83 8.68 8.52 8.37 8.22 8.08 7.94 7.8
18 9.45 9.29 9.12 8.96 8.8 8.65 8.5 8.35 8.2 8.06 7.91 7.77 7.64
19 9.26 9.1 8.94 8.78 8.63 8.47 8.32 8.18 8.03 7.89 7.75 7.62 7.48
20 9.08 8.92 8.76 8.61 8.45 8.3 8.16 8.01 7.87 7.73 7.6 7.46 7.33
21 8.9 8.74 8.59 8.44 8.29 8.14 8 7.86 7.72 7.58 7.45 7.32 7.19
22 8.73 8.57 8.42 8.27 8.13 7.98 7.84 7.71 7.57 7.44 7.31 7.18 7.05
23 8.56 8.41 8.26 8.12 7.97 7.83 7.69 7.56 7.43 7.29 7.17 7.04 6.92
24 8.4 8.25 8.11 7.96 7.82 7.69 7.55 7.42 7.29 7.16 7.03 6.91 6.79
25 8.24 8.1 7.96 7.82 7.68 7.54 7.41 7.28 7.15 7.03 6.9 6.78 6.66
26 8.09 7.95 7.81 7.67 7.54 7.41 7.28 7.15 7.02 6.9 6.78 6.65 6.54
27 7.95 7.81 7.67 7.54 7.4 7.27 7.14 7.02 6.9 6.77 6.65 6.54 6.42
28 7.81 7.67 7.53 7.4 7.27 7.14 7.02 6.89 6.77 6.65 6.54 6.42 6.31
29 7.67 7.54 7.4 7.27 7.14 7.02 6.9 6.77 6.65 6.54 6.42 6.31 6.2
30 7.54 7.41 7.28 7.15 7.02 6.9 6.78 6.66 6.54 6.42 6.31 6.2 6.09
31 7.41 7.28 7.15 7.03 6.9 6.78 6.66 6.54 6.43 6.32 6.2 6.09 5.99
32 7.29 7.16 7.03 6.91 6.79 6.66 6.54 6.43 6.32 6.21 6.1 5.99 5.89
33 7.17 7.04 6.92 6.79 6.67 6.56 6.43 6.33 6.22 6.11 6 5.89 5.79
34 7.05 6.92 6.8 6.68 6.56 6.45 6.34 6.22 6.11 6.01 5.9 5.8 5.69
35 6.93 6.81 6.69 6.57 6.46 6.34 6.23 6.12 6.02 5.91 5.81 5.7 5.6
36 6.82 6.7 6.59 6.47 6.36 6.24 6.13 6.03 5.92 5.82 5.71 5.61 5.51
37 6.72 6.6 6.48 6.37 6.26 6.15 6.04 5.93 5.83 5.72 6.62 5.52 5.43
38 6.61 6.49 6.38 6.27 6.16 6.05 5.94 5.84 5.74 5.63 5.53 5.44 5.34
39 6.51 6.39 6.28 6.17 6.06 5.96 5.85 5.75 5.65 5.55 5.45 5.35 5.26
40 6.41 6.3 6.19 6.08 5.97 5.86 5.76 5.66 5.56 5.46 5.37 5.27 5.18
CS511 Dissolved Oxygen Sensor 17

Table C-2: Dissolved oxygen solubility (mg/L) as a function of temperature
and salinity for moist air
Temp.
(° C)
SALINITY- in parts per thousand (ppt)
0 5 10 15 20 25 30 35 40
0 14.6 14.11 13.64 13.18 12.74 12.31 11.9 11.5 11.11
1 14.2 13.73 13.27 12.83 12.4 11.98 11.58 11.2 10.83
2 13.81 13.36 12.91 12.49 12.07 11.67 11.29 10.91 10.55
3 13.45 13 12.58 12.16 11.76 11.38 11 10.64 10.29
4 13.09 12.67 12.25 11.85 11.47 11.09 10.73 10.38 10.04
5 12.76 12.34 11.94 11.56 11.18 10.82 10.47 10.13 9.8
6 12.44 12.04 11.65 11.27 10.91 10.56 10.22 9.89 9.57
7 12.13 11.74 11.37 11 10.65 10.31 9.98 9.66 9.35
8 11.83 11.46 11.09 10.74 10.4 10.07 9.75 9.44 9.14
9 11.55 11.19 10.83 10.49 10.16 9.84 9.53 9.23 8.94
10 11.28 10.92 10.58 10.25 9.93 9.62 9.32 9.03 8.75
11 11.02 10.67 10.34 10.02 9.71 9.41 9.12 8.83 8.56
12 10.77 10.43 10.11 9.8 9.5 9.21 8.92 8.55 8.3
13 10.53 10.2 9.89 9.59 9.3 9.01 8.74 8.47 8.21
14 10.29 9.98 9.68 9.38 9.1 8.82 8.55 8.3 8.04
15 10.07 9.77 9.47 9.19 8.91 8.64 8.38 8.13 7.88
16 9.86 9.56 9.28 9 8.73 8.47 8.21 7.97 7.73
17 9.65 9.36 9.09 8.82 8.55 8.3 8.05 7.81 7.58
18 9.45 9.17 8.9 8.64 8.39 8.14 7.9 7.66 7.44
19 9.26 8.99 8.73 8.47 8.22 7.98 7.75 7.52 7.3
20 9.08 8.81 8.56 8.31 8.07 7.83 7.6 7.38 7.17
21 8.9 8.64 8.39 8.15 7.91 7.69 7.46 7.25 7.04
22 8.73 8.48 8.23 8 7.77 7.54 7.33 7.12 6.91
CS511 Dissolved Oxygen Sensor 18