Description and Specifications of PAA Sensor

Public Channel / Product Information

375 views
0 Likes
0 0
The peracetic acid (PAA) monitor is part of the ChemDAQ Steri-Trac® continuous gas monitoring system. The Steri-Trac system is modular and can employ various types of gas monitors, remote displays that mirror the output of the monitor, a DAQ computer for data collection, time weighted average alarms, exposure reports and graphing among other features.

Share on Social Networks

Share Link

Use permanent link to share in social media

Share with a friend

Please login to send this document by email!

Embed in your website

Select page to start with

1. ®   Page 1 of 2 SD-101-A-0.00 300 Business Center Drive • Pittsburgh, PA • 15205 phone 412.787.0202 • fax 412.788.2526 Description and Specifications of Peracetic Acid Monitor The peracetic acid (PAA) monitor is part of the ChemDAQ Steri-Trac ® continuous gas monitoring system. The Steri-Trac system is modular and can employ various types of gas monitors, remote displays that mirror th e output of the monitor, a DAQ computer for data collection, time weighted average al arms, exposure reports and graphing among other features. Monitors are available for several gases including PAA, ethylene oxide, hydrogen peroxide, ozone, combustible ga ses and oxygen, with more gases being introduced all the time. For more information see www.chemdaq.com. The Steri-Trac monitor consists of three part s, the sensor module, the monitor and the wall box. The monitor has a larg e digital display which is easily seen across the room. The monitor has two user adjustable alarms (audible & visual) and output relays to interface with other equipment. Each Steri- Trac monitor can be used as a stand-alone monitor or as part of the Steri-Trac gas monitoring system. The sensor module connects to the monitor with a snap on connection. It is designed to easily and quickly changed, without tools. Th e sensor module contains a sensor, analogue and digital circuitry, EEPROM for calibration parameters, battery and a chemical filter for gas specificity. In order to ensure accurate calibration of the PAA sensors, the sensor modules are calibrated at ChemDAQ and suppl ied to the customer about every four months. The old sensors are then returned to ChemDAQ to be tested, reconditioned and recalibrated. The PAA sensor is a three electrode ampero metric electrochemical sensor, held at a constant bias potential. The PAA vapor enters the sensor by diffusion and is electrochemically reduced at the working el ectrode to acetic acid. The resulting electric current is amplified, measured and converted to a digital signal for display on the monitor. The sensor is very selective towards peracetic acid, but there is still some cross sensitivity to hydrogen peroxide. Since hydrogen peroxi de is often present in significant concentrations where PAA is used, the sens or module also contains a chemical filter (patent pending) in fr ont of the sensor to remove th e hydrogen peroxide. This filter ensures that the sensor only responds to PAA. When the sensor module is returned to Chem DAQ, it is checked for correct operation, the filter is replaced and the sensor module is calibrated. Calibration is performed using PAA test gas generated in-house and validated by chemical titration against NIST traceable standards. The calibration pro cess is computer controlled, and all the calibration records are automatically stored in an Access data base and the calibration EEPROM parameters in the sensor module are automatically update d. Calibration certificat es are generated for sensor modules that pass all the calibration cr iteria and these are sh ipped with the sensors for the end-user’s records.

2. ®   Page 2 of 2 SD-101-A-0.00 300 Business Center Drive • Pittsburgh, PA • 15205 phone 412.787.0202 • fax 412.788.2526 PAA Sensor Module Specifications with Filt er to Remove Hydrogen Peroxide Vapor Parameter Specifications Notes Sensor type 3 Electrode, amperometric Response Time (T 50 ) <20s 5 minute exposure Response Time (T 90 ) < 50s 5 minute exposure Linearity Linear over range Range 0 – 3 ppm Display Resolution 0.01 ppm Display resolution may be finer than accuracy of the sensor module. Repeatability < the greater of +/-0.02 ppm or 5% of signal Applying test gas within range on to sensor repeatedly for 5 minute on/off cycles Lowest Detection Limit 0.04 ppm Accuracy < +/- 0.04 ppm or 10% of signal Steady state, accuracy relative to calibration. Temperature Range -20 to 40 o C Zero shift with temperature < +/- 0.04 ppm Steady state Effect of Temperature on span < +/- the greater of 0.02 ppm or 5% of signal Steady state Relative Humidity Range 15 to 95 % non-condensing Prolonged exposure to very high or very low humidity should be avoided. Effect of humidity on baseline < +/- 0.02 ppm PAA equivalent 15 to 95 % humidity ch ange (steady state)

Views

  • 375 Total Views
  • 307 Website Views
  • 68 Embedded Views

Actions

  • 0 Social Shares
  • 0 Likes
  • 0 Dislikes
  • 0 Comments

Share count

  • 0 Facebook
  • 0 Twitter
  • 0 LinkedIn
  • 0 Google+

Embeds 1

  • 1 www.chemdaq.com