APHA/PT-Co (Hazen) Color Analyzer

Complete Analytical System for Measuring APHA/Platinum-Cobalt Color (ASTM D1209)

This test method describes a procedure for the visual measurement of the color of light colored liquids. It can be referred to by several different names: APHA, Platinum-Cobalt, or Hazen. The measurement was originally developed to detect contamination of water supplies as detected by a slight yellow color. Today it finds use in many industries to measure slight yellowness to determine product quality (either degradation or impurities).

The APHA/Platinum-Cobalt color scale is described in ASTM D1209 “Standard TestMethod for Color of Clear Liquids (Platinum-Cobalt Scale)”. This ASTM method is an off-line manual laboratory method. The original test design required an observer to compare the color of a product to a known standard, and then judge the “color.” The APHA/Platinum-Cobalt color scale ranges from 0 to 500. The lowest value of 0 is referred to as water white. value of 500 is distinctly yellow.

Using a Guided Wave APHA/Platinum-Cobalt Color Analyzer system to automate this measurement within a process eliminates the visual judgment of a technician and delivers online real-time process control information to the process operators.

System Configuration

The Guided Wave Saybolt Color Analyzer system is a complete solution. The “ready-to-go” analytical system includes:

  • Analyzer - ClearView® db filter photometer technology
  • Fiber optic cables
  • Sample interface - insertion probe or flow cell
  • Control software and Saybolt application calibration

Accurate, Real-time Reliable Results

The APHA/Platinum-Cobalt Color Analyzer system utilizes a Guided Wave multi-wavelength ClearView db filter photometer analyzer platform. It may be configured for either one (1) or two (2) independent sample monitoring points. The ClearView db analyzer is configured with application-appropriate wavelengths to measure the APHA/Platinum-Cobalt color of the sample. The analyzer employs a dual-beam design – meaning; the system has an continual internal optical reference check that allows it to self-compensate for signal variation due to non-sample conditions. This ultimately provides the system with long term stability. The final product is a total APHA/Platinum-Cobalt Color System that measures the color variation without interference from other factors.

Figure 1 shows an initial calibration chart showing the measured values as compared to laboratory standard values.

APHA/ Platinum-Cobalt (Hazen) Color Analyzer Enclosure Options

Complete APHA/Platinum-Cobalt (Hazen) Color Analyzer System

  • Unique dual beam optics - for long term, stable operation
  • Up to two (2) independent measurement points -  for added analytical flexibility at reduced cost per point
  • High efficiency yet rugged fiber optics - analyzer electronics can be located away from a hazardous sample point
  • In-door touch screen or Ethernet (Modbus TCP) - easy local or remote analyzer operation and control
  •  Analytical calculations are all encoded in the software - answers and alarms are clearly reported

Reliable, Rugged, and Flexible

By partnering with Guided Wave you gain the advantage of 35+ years of experience in online process monitoring and stream sample analysis. Our entire product line is designed and developed to meet the challenges of the most demanding production environments. The Pulsed Xenon source lamp used in the Benchtop 508plus has a lifetime lasting over two years.

The Smart Choice

Guided Wave’s APHA/Platinum-Cobalt Analyzer system delivers  accurate, real-time process measurement results. Its linearity and repeatability, as well as its low maintenance requirements  make it a cost effective, smart choice to help optimize production, improve yields, ensure consistent product quality and enhance profitability.

Options for a Custom Solution

Another advantage of the Saybolt Analyzer system is that is can be customized in many ways. For more information about specifications and analyzer operations request ClearView db
document #1033 or call Guided Wave.

Proof of Continuous Accurate APHA/Platinum-Cobalt (Hazen) Color Measurement

Specifications: APHA/Pt-Co (Hazen) Color Analyzer - Photometer

Analyzer TechnologyFiber optic dual-beam ClearView db photometer (see also document #1033)
Fiber Connectors SMA 905
Light Source Tungsten-Halogen, >4000 hours typical
Photometric Noise<50 µAU 450-2100 nm 1 minute rms
Photometric Drift <500 µAU rms/ °C
Response Time 1 second, minimum. User settable
Measurement Range0-500 APHA/Platinum-Cobalt units (Pathlength can be optimized to increae sensitivity)
Measurement AccuracyComplies with ASTM method D1209
Power 24 VDC, 3 A; 72 watts
Environmental 0 – 45°C, 0 – 90%, sun and rain sheltered
Channels Up to 2 (two) sample channels and optional turbidity monitoring
Outputs (analog)Up to 6 for a one channel unit, Up to 4 per channel for a two channel unit, 4 – 20 mA, customer powered
Outputs (discreet)Up to 6 for a 1 channel unit, Up to 4 per channel for a 2 channel unit, contact closures
Inputs (analog) 4 (optional) 4 – 20 mA, isolated grounds
Local Display LCD touch screen, color QVGA
CommunicationsEthernet (TCP Modbus) standard
Enclosures General Purpose NEMA 4 unclassified, Z-Purge, NEMA 4x, CI D2, X-Proof, ICEEx, ATEX, CI D1