TI00448C/07/EN/14.21
71530030
2021-06-30

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TOCII CA72TOC
Analyzer for online measurement of TOC inaqueous media using thermic catalytic combustion

Application• Monitoring of industrial wastewater, in the inlet and outlet• Control of process wastewater• Monitoring of surface run-off in industrial systems• Monitoring of surface run-off in airports• Municipal wastewater monitoring• Measurement of carbon load for nutrient dosingYour benefits• Optimized for industrial applications even with fluctuating pH values and high saltloads
• Fast and easy maintenance due to easy accessibility of all components• Available measuring ranges between 0.25 mg/l and 12,000 mg/l TOC, can beextended by predilution• pH-controlled acid dosing for TIC stripping minimizes acid consumption• Measurement performed using "double-batch" method• One- and two-channel measurement available• Heated salt trap significantly increases operating time
• Externally controlled self-monitoring with TOC standard, e.g. for limit violation

TOCII CA72TOC

Function and system designMeasuring principle

TOC as sum parameter
The total carbon (TC) of an aqueous sample is divided into total inorganic carbon (TIC) and totalorganic carbon (TOC).
TOC can be divided into three groups:• Dissolved organic carbon (DOC)• Non-purgeable organic carbon (NPOC)• Purgeable organic carbon (POC)
It is important to note the difference between POC and VOC (volatile organic carbon). POC is actively
eliminated during TOC online analysis (e.g. during stripping). VOC is a scientific term that describes
the properties of volatile organic carbons. The volatility of substances is a passive process and isstrongly influenced by temperature and pressure.

TCTOC

TIC

DIC

NPOC

1DOC

POC

2A0045995

1Classification of carbon parameters

TC

Total carbon

NPOC

Non-purgeable organic carbon (NPOC)

TIC

Total inorganic carbon

POC

Purgeable organic carbon

TOC

Total organic carbon

DOC

Dissolved organic carbon

DIC

Dissolved inorganic carbon

2

Particulate organic carbon

1Particulate inorganic carbon

Measurement method
The analyzer determines the TOC (total organic carbon) content of an aqueous sample. This is done
through thermic catalytic combustion followed by NDIR (non-dispersive infrared) detection of theresulting CO2. The TOC parameter describes the total organic load of water, is an indicator of water
quality and can serve as the basis for calculating wastewater charges.
The analyzer works with two interconnected circuits, the liquid circuit and the gas circuit, todetermine TOC using the direct method. In the liquid circuit, the sample is fed into the analyzer
where it can be optionally diluted in the event of high salt loads or TOC values. The sample is thenacidified and the inorganic carbon is eliminated by purging (stripping). The sample is then passed
through a rotating slit filter, in which the particulate solids are removed in compliance with DIN
standards, and dosed into the combustion furnace. The sample is incinerated in the combustion
furnace at 850 °C (1550 °F). The combustion gas is then cooled in stages and the CO2 content isdetermined in the NDIR detector. Using the "double-batch" method, the reactor and the gas circuit are
flushed with CO2-free carrier gas prior to the next measurement and the baseline is determinedwhile the next sample is prepared in the liquid circuit.
Measurement, calibration and adjustment
To monitor the measurement, a single-point calibration can be triggered externally or by a timer. Atwo-point adjustment can be used to adapt the analyzer to system changes.

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TOCII CA72TOC

Two-channel measuring principle
Two-channel measurement makes it possible to measure two different sample streams in a device,e.g. two inlets of a wastewater treatment plant. This option is recommended for sample streams
with similar measuring ranges.
Measuring system

A complete measuring system comprises:• Sample preparation system• CO2 scrubber• Analyzer

2345

16A0045994

2123456

Dependability

Complete measuring systemSample
Sample conditioning
Analyzer
CO2 scrubber
Gas supply
Water supply

Reliability
Heated salt trap
The heated salt trap option is used for easy maintenance in the case of samples with high salt loads.
Incineration of these samples can lead to buildup on the catalyst and furnace and thus compromise
the results.
With the heated salt trap, it is possible to remove salts from the furnace quickly and efficiently. This
results in a dramatic increase in availability. Furthermore, operating costs are reduced throughlonger maintenance cycles and easy operation of the salt trap. The salt trap can be easily removed
from the furnace, without having to switch off the furnace. The salts in the trap can be easily
removed and the cleaned trap reattached.
pH-controlled acid dosing
One advantage of pH-controlled acid dosing is that only the quantity of acid needed to reach a pH
value of 2.5 is added to the sample. Excess dosing does not occur. This reduces the amount of acidneeded while also minimizing the salt that is released into the furnace through excess acid. In
municipal wastewater treatment plants, the absence of humic acid precipitation is guaranteed. This
rules out the potential for readings to be higher than expected.
Integrity
Double-batch method
With the patented double-batch method, the two circuits (water and gas) are linked. The aqueous
sample stream is continuously prepared in the analyzer and fed into the furnace in batches. During
measurement, the CO2-containing gas is circulated and accumulated in the gas circuit. This makes it
possible to record large sample volumes (1200 µl), which results in a high level of sensitivity. Oncemeasurement is complete, the gas circuit is flushed with CO2-free carrier gas and the baseline for thenext measurement is determined.

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TOCII CA72TOC

Input
Measured variable

Total organic carbon (TOC)

Measuring range• CA72TOC-A: 0.25 to 600 mg/l TOC• CA72TOC-B: 1 to 2400 mg/l TOC• CA72TOC-C: 2.5 to 6000 mg/l TOC• CA72TOC-D: 5 to 12 000 mg/l TOC
With optional predilution, the measuring range can be expanded by a factor of 20.

Input signal

8 signal inputs 24 V DC, active, load max. 500 Ω
Input #1

Service, trigger calibration

Input #2

Service, trigger adjustment

Input #3

Service, trigger screen flush

Input #4

Service, trigger power flush

Input #5

Not assigned

Input #6

Not assigned

Input #7

Trigger standby

Input #8

Trigger channel switchover (optional)

OutputOutput signal

Measuring channel 1
0/4 to 20 mA, galvanically isolated
Measuring channel 2 (optional)
0/4 to 20 mA, galvanically isolated

Signal on alarm

4 outputs:• Limit value alarm• Fault message• Standby message• Operational control
Floating, normally closed (max. 0.25 A / 50 V)

LoadMax. 500 Ω

Data interface• RS 232 C, proprietary, for data output and remote operation (optional)• USB

Power supply
Supply voltage

115/230 V AC, 50/60 Hz

Power consumption

800 VA

Fuses

Power distribution
2.5 A, slow-blow, design: fine-wire fuse 6.3 x 32

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TOCII CA72TOC

Relays4 A per relay, slow-blow, design: TR5
Power unit
2 A, slow-blow, design: fine-wire fuse 5 x 20Performance characteristics 1)
Measured value resolution

1.1 %, resolution limit at 20 % of the measuring range (LDC)
4.6 %, resolution limit at 80 % of the measuring range (LDC)

Maximum measured error

0.4 %, systematic measured value deviation at 20 % of the measuring range (BIAS)
2.4 %, systematic measured value deviation at 80 % of the measuring range (BIAS)

Repeatability

0.4 %, repeatability precision at 20 % of the measuring range
1.6 %, repeatability precision at 80 % of the measuring range

Short-term drift

0.5 %/day

Limit of detection LOD

0.75 % of end of measuring range

Limit of quantification LOQ

2.5 % of end of measuring range

Installation
Mounting location

The analyzer can be mounted in three different ways:• Bench mounting• Wall mounting• On a base frame‣ Mount the device in such a way that it is also accessible from the rear for maintenance purposes.
Installation instructions

The analyzer requires a drain beneath the device.
‣ Use a 6/8 mm drain pipe made of PTFE. No backpressure should form in the drain.
Halogens or other vapors may not build up in enclosed spaces.
‣ Use an exhaust gas connection. No backpressure should form in the 4/6 mm exhaust gas hose.

‣ Avoid exposure to direct sunlight.
‣ Observe ambient conditions (technical data).
Compressed air and water supply
Compressed air supply‣ Only use CO2-free air to operate the analyzer.
The air must be dry and oil-free and must meet the following conditions:• < 3 ppm CO2• < 3 ppm hydrocarbons• Constant pressure of 2 bar (29 psi)
• Pressure tolerance ± 5 %1)

The performance characteristics have been determined in accordance with ISO 15839, Annex B. 300 µl of sample were metered into theCA72TOC-B1A0B1 per measurement. This resulted in a measuring range from 4 to 800 mg/l. The following data refer to this device. Slightdeviations should be factored in if applying the performance characteristics to other measuring ranges.

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TOCII CA72TOC

The compressed air supply must be fitted with a CO2 scrubber and a pressure regulator.
• Connection: 4/6 mm DN• Required quantity of compressed air:• 600 l/h (21.2 ft3/h) for the gas generator CO2 adsorber (Domnick Hunter, inlet pressure 5 to
16 bar (73 to 232 psi))• 60 l/h (2.12 ft3/h) for the soda-lime CO2 scrubber (inlet pressure 4 to 10 bar (58 to 145 psi))
Water supply
A water connection is absolutely essential for the correct operation of the CA72TOC analyzer.
• The water is connected via a 6/8 mm DN or G3/8 coupling• Pressure is between 2 and 4 bar (29 to 58 psi), except for the version with sample dilution• Version with sample predilution:• Use deionized water (DI water) or drinking water with a water hardness level < 10 °dH (< 179ppm CaCO3).
• Pressure 3 ± 0.2 bar (43.5 ± 3 psi)
Gas flow
Circuit gas
The flowmeter for the circuit gas is used to perform function checks and is set at the factory. Theflow rate during operation is between 0.7 and 1.2 l/min (1.5 to 2.5 ft3/h).
Carrier gas
The volume flow for the carrier gas is regulated using a precision restrictor. The flow is approx.
0.8 l/min (1.7 ft3/h) at a pressure of 2 bar (29 psi).
Stripping gas
The volume flow for the stripping gas is regulated also using a precision restrictor. The flow isapprox. 0.15 l/min (0.3 ft3/h) at a pressure of 2 bar (29 psi).

Environment
Ambient temperature range+5 to 35 °C (41 to 95 °F)

Humidity

20 to 80 %, non-condensing

Degree of protection

IP54

Electromagneticcompatibility

Interference emission and interference immunity as per EN 61326-1:2013, Class A for Industry

Process
Medium temperature range

4 to 40 °C (39 to 104 °F)

Medium pressure range

Non-pressurized infeed to the analyzer from sample preparation

Sample flow rate

20 ml/min (0.32 US gal/h)

Sample consistency

Water-based
Flammable substances must not occur in combustible concentrations. Sample dilution is thennecessary.

Sample feeder volume

6

90 ml (3 fl.oz)

Endress+Hauser

TOCII CA72TOC

Mechanical construction
Design, dimensions

785 (30.9)

405 (15.94)

990 (39.0)

1505 (59.3)

1600 .. 1620 (63.0 ... 63.8)*600 (23.6)

A0023087

3*

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Dimensions in mm (in)Depending on sample preparation

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TOCII CA72TOC

93 ... 112 (3.66 ... 4.41)*

894 (35.2)

A0035444

4*Dimensions in mm (in)Depending on sample preparation

WeightApprox. 75 kg (165 lbs)

Materials

Housing

Aluminum, powder-coated

Front window

Glass, conductive coating

Valve seals

EPDM, FPM, FFKM

Pump hoses

Ismaprene

Pump and pump seals

PTFE, FFKM

Reagent and sample hoses

PTFE, PE

Exhaust gas and ventilation hoses

PTFE, PE

Outflow hoses

PTFE

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TOCII CA72TOC

Operability
Local operation

124

3
A0025242

51234

Operating elements
Main switch
Numerical keypad
USB port
Screen, 16 lines with 40 characters per line

Certificates and approvals
Current certificates and approvals for the product are available via the Product Configurator atwww.endress.com.
1.

Select the product using the filters and search field.

2.

Open the product page.

The Configuration button opens the Product Configurator.

Ordering information
Product pagewww.endress.com/CA72TOC

Product Configurator

On the product page there is a Configure button to the right of the product image.
1.

Click this button.
 The Configurator opens in a separate window.

2.

Select all the options to configure the device in line with your requirements.
 In this way, you receive a valid and complete order code for the device.

3.

Export the order code as a PDF or Excel file. To do so, click the appropriate button on the rightabove the selection window.
For many products you also have the option of downloading CAD or 2D drawings of theselected product version. Click the CAD tab for this and select the desired file type using
picklists.

Scope of delivery

Endress+Hauser

The scope of delivery comprises:• 1 analyzer in the version ordered• 1 accessories package for leak test
• Tool kit for glass ball and media removal• Accessories for acid filter• Accessories for commissioning the strip and separation chamber• Accessories for combustion furnace maintenance• Hose set• 1 canister, 5 liter• 2 canisters, 2 liter• Set of cabinet keys

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TOCII CA72TOC• 10 ml graduated cylinder• Sponge cloth• Protective goggles• Gloves, acid-proof and base-proof• Protective gloves, heat-resistant• Silicone grease• 1 x Operating Instructions‣ If you have any queries:
Please contact your supplier or local sales center.

Accessories
The following are the most important accessories available at the time this documentation wasissued.

‣ For accessories not listed here, please contact your Service or Sales Center.
Device-specific accessories

Retrofitting of dilution unit
• To be used in the event of high salt loads or high measured values• Order number: 71189243
Retrofitting of salt trap, type II• To be used in the event of high salt loads• Order number: 71375329
Conversion of PA-2 to PA-3
• To be used with sample flow volumes of 0.1 – 1 m³/h
• Order number: 71295866
Sample conditioning PA-9 PP• Recommended for problematic wastewater due to its high chemical resistance properties (exceptin the case of oxidizing acids and halogens)• Order number: 71101588
CO2 scrubber, soda lime
• Can be used as a replacement for the Parker CO2 adsorber• Order number: 71232260
Pipe backflushing• To be used in the event of severe deposit formation in the inlet from the bypass to the MV 1
• Order number: 71414592

Service-specific accessories

Reagent and parent solutions• CAY450-V10AAE, 1000 ml stripping reagent for CA72TOC• CAY451-V10C01AAE, 1000 ml parent solution (KHP) 5 000 mg/l TOC• CAY451-V10C10AAE, 1000 ml parent solution (citric acid) 100 000 mg/l TOC
High-quality buffer solutions from Endress+Hauser - CPY20
The secondary buffer solutions have been referenced to primary reference material of the PTB(German Federal Physico-technical Institute) or to standard reference material of NIST (NationalInstitute of Standards and Technology) according to DIN 19266 by a laboratory accredited by theDAkkS (German accreditation body) according to DIN 17025.
Product Configurator on the product page: www.endress.com/cpy20

System components

10

Kit CA72TOC heated salt trap
• For replacement for maintenance tasks (shortens the maintenance time) or as a substitute• Order number: 71101532

Endress+Hauser

*71530030*71530030

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