Liquiline System CA80CR

Summary

Product identification

The Liquiline System CA80CR is a wet-chemical analyzer designed for the near-continuous determination of chromate (Cr (VI)) in liquid media.

Application

This analyzer is suitable for:

• Optimizing the treatment efficiency of industrial wastewater treatment plants
• Monitoring drinking water
• Monitoring membrane filtration systems
• Monitoring limit values for industrial wastewater discharge

A "Cabinet, outdoor version" product variant is available for outdoor setup, mounting, and operation.

Key Features

• Integrated controller with up to 2 measuring channels
• Digital Memosens technology
• Easy upgrade to a measuring station by connecting up to 4 Memosens sensors
• Two-channel device option
• Digital fieldbuses supported: PROFINET, PROFIBUS DP, Modbus TCP, Modbus RS485, and Ethernet IP
• Web server functionality
• Simple, tool-free maintenance

Measuring Principle

The analyzer uses a colorimetric measuring principle. A specific color reagent is added to a prepared sample in a mixing/reaction chamber. The resulting color change is measured by a multispectral photometer based on light absorption. A reference measurement is performed to compensate for interference influences.

Chromium and Chromate

The document notes that chromium exists in trivalent (Cr³⁺) and hexavalent (chromate, CrO₄²⁻ and dichromate, Cr₂O₇²⁻) forms. Cr(VI) is a known carcinogen, while Cr(III) has low toxicity. Limit values for chromate concentration are stipulated by national standards (e.g., German drinking water ordinance for total chromium at 50 µg/l, and limits for industrial wastewater like 2 mg/l for tanneries and 0.1 mg/l for electroplating plants).

Photometric Determination of Chromate

The analyzer utilizes the diphenylcarbazide method. Chromate (Cr(VI)) reacts with diphenylcarbazide in an acidic solution to form a red-violet chelate complex. This method specifically records Cr(VI) ions.

Cross-sensitivity

The document lists ions and substances checked for cross-sensitivity with specified concentrations. No cross-sensitivities were observed up to these limits. Some ions (Fe³⁺, Fe²⁺, Cu²⁺, Sn²⁺) were noted to decrease the measured value.

• Cl⁻: 15,000 mg/l (ppm)
• Na⁺: 10,000 mg/l (ppm)
• K⁺, Ca²⁺: 500 mg/l (ppm)
• Ag⁺: 100 mg/l (ppm)
• Cd²⁺: 70 mg/l (ppm)
• SO₄²⁻, CO₃²⁻, NO₃⁻, Zn²⁺, Ni²⁺, CO₂²⁺: 50 mg/l (ppm)
• Hg²⁺: 5 mg/l (ppm)
• Turbidity: 50 NTU
• pH: 4 to 12
• Hardness: 70 °dH

Measuring System

A complete measuring system includes the Liquiline System CA80CR analyzer, reagents, cleaner, standard solution, and optionally, sample conditioning systems like Liquiline System CAT8x0 (microfiltration or membrane filtration).

Input

• Measured Variables: Chromate (Cr(VI)), CrO₄ [mg/l, µg/l, ppm, ppb]
• Measuring Range:
  • CA80CR-**AF: 0.03 to 2.5 mg/l Cr(VI)
  • CA80CR-**AG: 0.2 to 5.0 mg/l Cr(VI)
• Types of Input:
  • 1 or 2 measuring channels (analyzer main parameter)
  • 1 to 4 digital sensor inputs for Memosens protocol sensors (optional)
  • Analog current inputs (optional)
  • Binary inputs (optional)
• Input Signal:
  • 2 x 0/4 to 20 mA (optional), passive, potentially isolated
• Current Input, Passive:
  • Span: > 0 to 20 mA
  • Signal Characteristic: Linear
  • Internal Resistance: Non-linear
  • Test Voltage: 500 V
• Cable Specification (for optional sensors with Memosens technology):
  • Cable Type: Memosens data cable CYK10 or sensor fixed cable
  • Cable Length: Max. 100 m (330 ft)

Output

• Output Signal:
  • 2 x 0/4 to 20 mA, active, potentially isolated (standard)
  • 4 x 0/4 to 20 mA, active, potentially isolated (with 2 additional analog outputs)
  • 6 x 0/4 to 20 mA, active, potentially isolated (with 4 additional analog outputs)
  • Binary outputs
• Signal on Alarm: Adjustable per NAMUR Recommendation NE 43. Failure current adjustable from 0 to 23 mA (in 0-20 mA range) or 2.4 to 23 mA (in 4-20 mA range). Factory setting for failure current is 21.5 mA.
• Load: Max. 500 Ω
• Current Outputs, Active:
  • Span: 0 to 23 mA
  • Signal Characteristic: Linear
  • Output Voltage: Max. 24 V
  • Test Voltage: 500 V
• Relay Outputs:
  • 1 x single-pin changeover contact (alarm relay)
  • 2 or 4 x single-pin changeover contacts (optional)
  • Maximum load for alarm relay: 0.5 A
  • Maximum load for other relays: 2.0 A

Protocol-specific Data

The device supports several communication protocols:

• PROFIBUS DP: Profile 3.02, supports up to 16 AI and 8 DI blocks, 4 AO and 8 DO blocks.
• Modbus RS485: RTU/ASCII protocol, supports function codes 03, 04, 06, 08, 16, 23.
• Modbus TCP: TCP port 502, supports function codes 03, 04, 06, 08, 16, 23. Configurable via DHCP or menu.
• Web server: Accessible via standard WiFi/WLAN/LAN/GSM or 3G routers with a user-defined IP address. TCP port 80.
• EtherNet/IP: ODVA certified. Supports CIP connections and explicit messages.
• PROFINET: PNIO Version 2.34, 100 MBit/s. Conformance Class B, Netload Class II.

Power Supply

• Supply Voltage:
  • 100 to 120 V AC / 200 to 240 V AC or 24 V DC (24 V DC not available for "Outdoor" version)
  • 50 or 60 Hz
• Power Consumption: Varies by version (e.g., 130 VA for non-outdoor versions without heating, up to 680 VA for outdoor versions with cooling). 24-V version: max. 105 W.

Mechanical Construction

• Dimensions: Drawings provided for closed version, open version, and with base.
• Weight: Varies by order configuration (e.g., Cabinet version: 39.5 kg, Analyzer stand: 72.5 kg).
• Materials:
  • Parts not in contact with medium: ASA + PC, PP, Safety glass, EPP, Powder-coated sheet steel.
  • Parts in contact with medium: PP, TPE, FKM, C-Flex (TPE), NORPRENE (PP).

Process Connection

• Sample Inlet: Plug-in connector for rigid hoses (OD 4 mm) or hose barb for flexible hoses (ID 1.6 mm).
• Dilution Water: Hose barb for flexible hoses (ID 3.2 mm).
• Outlet: Hose barb for flexible hoses (ID 13 mm).

Operability

• Operation Concept: Intuitive operation with navigator and soft keys, plain-text display.
• Display: Graphic display (240 x 160 pixel) with backlight and alarm indication.

Environment

• Ambient Temperature Range:
  • Standard housing versions: +5 to +40 °C (41 to 104 °F)
  • Outdoor version: -20 to +40 °C (-4 to 104 °F)
• Storage Temperature: –20 to 60 °C (–4 to 140 °F)
• Relative Humidity: 10 to 95 %, non-condensing
• Degree of Protection: IP55 (cabinet, analyzer stand), TYPE 3R (cabinet, analyzer stand)
• Electromagnetic Compatibility: EN 61326-1, class A for industrial areas.
• Electrical Safety: EN/IEC 61010-1:2010, Class I equipment.
• Pollution Degree: Pollution level 2.

Process

• Sample Temperature: 4 to 40 °C (39 to 104 °F)
• Consistency of the Sample: Low solids content (turbidity < 50 NTU), aqueous, homogenized.
• Sample Supply: Unpressurized.

Performance Characteristics

• Maximum Measured Error: 2 % of end of measuring range. With dilution and dilution factor 5, an additional 3.0 % of end of measuring range is added.
• Repeatability:
  • Up to 0.5 mg/l (ppm) Cr(VI): ± 10 µg/l (ppb) Cr(VI)
  • ≥ 0.5 mg/l (ppm) Cr(VI): ± 2 % of the display value
  • With dilution and dilution factor 5: Additionally 1.5 % of end of measuring range.
• Measuring Interval: Continuous (approx. 5 min), adjustable from 10 min to 24 h.
• Sample Requirement:
  • Without dilution module: 22 ml (0.74 fl oz)/measurement.
  • With dilution module: Sample: 11 to 15 ml (0.37 to 0.51 fl oz)/measurement; Dilution water: 17 to 21 ml (0.57 to 0.71)/measurement.
• Reagent Requirement: Approx. 65 μl per reagent and measurement.
• Calibration Interval: 1 h to 90 days, depending on application and ambient conditions.
• Maintenance Interval: Every 3 to 6 months, depending on application.

Disclaimer: Extraction may miss figures, footnotes, or revisions; contractual data must match the OEM PDF revision used on the project.

Official datasheet (PDF)

Lenntech datasheet mirror