Because of their unique combination of advantages, Picarro WS-CRDS analyzers are now displacing several traditional technologies in different applications. The charts below summarize WS-CRDS as compared against these older, competitive technologies, in terms of sensitivity, selectivity (specificity), accuracy, cost, ease of use, and speed. WS-CRDS also compares favorably with these other methods in terms of practical advantages such as ease of use, rugged packaging and lightweight portability. Picarro WS-CRDS analyzers are fully self-contained and can be operating within minutes of setup by even inexperienced users. They include Ethernet connectivity supporting remote automated operation and use this to synchronize data to an atomic clock service.

Advantages and Benefits

  • High sensitivity and precision - allows ultra-trace gas detection
  • Extremely low drift yielding high accuracy with very infrequent calibration
  • High linearity
  • Insensitive to environmental temperature and pressure changes and vibration
  • Significantly lower cost of ownership than many competing technologies
  • High dynamic range -- concentrations and isotopic ratios over a large range of concentrations (ppt to %)
  • Multiple isotopes and gas species in a single, fast measurement
  • Requires no sample preparation
  • Continuous sample flow / measurements
  • High reliability, easy to use, up an running in minutes
  • Interference free
  • No consumables required
  • Field & laboratory deployable

Ease of Use and Installation and Calibration Protocol


The typical installation protocol is unbelievably simple:

  1. Take the analyzer out of the box
  2. Connect and plug in power cables and vacuum line (from internal pump to analyzer)
  3. Analyzer starts itself, warms up, performs diagnostics, and begins taking data
  4. Data is displayed in real time and archived in an ASCII file each day

And because the analyzer is incredibly linear, the calibration protocol is similarly simple:

  1. Insert zero-level (or low-level) calibration standard from gas bottle or permeation tube and read measurement on analyzer
  2. Perform similar step for high-level calibration standard
  3. Based on the difference between analyzer's readings and calibration standard values, set new calibration value

Quality & Reliability


Reliability is a core imperative at Picarro. It's part of our heritage, coming from the telecom industry where reliability is a given. We design and build for reliability at every step -- as we proceed with product development, and then move the new device from prototyping, through field trials, pilot manufacturing and into full-scale production. Detailed failure mode effects analysis (FMEA) is woven in as a key part of this overall effort. Our devotion to reliability yields superior products for our customers, and is our pledge to you.

Picarro's comprehensive reliability program consists of four stages with specific elements defined for each stage.

  1. Components and Materials
    Component Qualification (Life/Stress Testing)
    Supplier Qualification
    Incoming Inspection
  2. Assembly Process
    Design for Manufacturability
    Process Validation
    Process Monitoring/Control (SPC)
  3. Assembled Systems
    Design Validation
    Physical Integrity Testing
    Compliance Testing
  4. Controlled System
    Environmental and Stress Testing
    Life Testing (including Production Surveillance)
    Field Performance Monitoring and Surveillance

Environmental, Shock and Vibration Testing for Every Analyzer

Every instrument that we ship undergoes the following stress testing:

Thermal Environmental Testing (whole instrument):
> 12 hours 5º - 40ºC operational temperature step testing (performance specifications verified over this range)

1 week 30º - 40ºC long-term operational temperature step testing (performance specifications verified over this range)

-10ºC and 50ºC soak testing, non-operational

Component Thermal Cycling (optical components): 35º - 65ºC temperature cycling

Vibration Testing
2 axis, 25 Hz, 1gp-p acceleration, 15 minutes each axis

Shock Testing
Bench handling (MIL-STD 810F): pivoted edge drops onto a hard surface (laboratory bench), 4" height, 12 edges (x,y,z axes), 2 drops each edge

Power Interruption Testing
> 5 AC power cycle startups

Data showing how WS-CRDS is immune to interferences from changing concentrations of other molecular species (such as water vapor) in the background gas, as compared with such interferences which are typical with NDIR-based instruments.

Data showing how WS-CRDS is immune to interferences from changing concentrations of other molecular species in the background gas as compared with such interferences which are typical with UV-fluorescence-based instruments.