A measuring setup with a differential generator photoionization detector for determining biomarkers in exhaled gas

In the space restricted airtight environment that people lives in, detecting harmful gas by miniature gas chromatography is the practical requirement at present, however, PIDs performance is key factor that restrict the application of miniature gas chromatography, the redesign of the detectors gas route in this paper aiming at improve detectors stability observably, and schemed out miniature PID with high sensitivity, low detection limit and fast response. The result of the experiment shows that the detection limit is 0.04ppm, the sensitivity is 101mv/ppm,the stability is 0.04×10-6/24h,meeting the project requirement. Keywords: photoionization detector; ionization chamber; sensitivity; detection limit;

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Evaluation of direct reading photoionization detector performance under various operational parameters

Environmental Health Engineering and Management ◽

10.34172/ehem.2021.15 ◽

2021 ◽

Vol 8 (2) ◽

pp. 123-128

Author(s):

Amir Hossein Khoshakhlagh ◽

Farideh Golbabaei ◽

Mojtaba Beygzadeh ◽

Francisco Carrasco-Marín ◽

Seyed Jamaleddin Shahtaheri

Keyword(s):

Relative Humidity ◽

Dynamic Range ◽

Reference Method ◽

Operational Parameters ◽

Direct Reading ◽

Detector Performance ◽

Vapor Detection ◽

Sample Concentration ◽

Photoionization Detector ◽

Before And After

Background: A hand-held portable direct-reading monitor, including photoionization detector (PID) is renowned for its good sensitivity, considerable dynamic range, and nondestructive vapor detection ability in comparison to the tardy response of the PID in gas chromatography (GC), which its application has been restricted. In this study, the performance of a PID system (MultiRAE Lite) was evaluated as a replacement of GC in the measurement of toluene in a dynamic adsorption system. Methods: The test was done at different relative humidity levels (30%, 50%, and 80%), temperatures (21, 30, 40° C), and toluene concentrations (20, 100, 200, and 400 ppm). Results: The PID achieved 48% of all measurements meeting the comparison criterion. The results showed that the performance of the PID could be altered by the variables. The best performance of the PID was at temperature of 21° C, the relative humidity of 50%, and concentration of 200 ppm with the percentage of readings achieving the criterion of comparison to 58%, 54%, and 52%, respectively. The averages of the PID readings (mean ± SD at 200 ppm= 207.9 ± 8.7) were higher than the reference method measurements averages (mean ± SD at 200 ppm= 203.5 ± 5.8). The regression analysis of the toluene results from the PID and the reference method results indicated that the measurements were significantly correlated (r2 = 0.93). Conclusion: According to the results, the device response is linear. Therefore, the findings are acceptable in adsorption studies. In this way, the measurement of the sample concentration should be performed using the same instrument before and after the reactor in order to calculate the adsorption efficiency.

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High resolution rainfall – runoff measurement setup for green roof experiments in a tropical environment

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-7-9367-2010 ◽

2010 ◽

Vol 7 (6) ◽

pp. 9367-9410 ◽

Cited By ~ 2

Author(s):

T. Vergroesen ◽

U. Man Joshi ◽

N. C. van de Giesen ◽

F. H. M. van de Ven

Keyword(s):

High Resolution ◽

Green Roof ◽

Rain Gauge ◽

Tropical Environment ◽

Rainfall Runoff ◽

External Disturbances ◽

Data Treatment ◽

Measuring Setup

Abstract. This article describes the measurement setup that is used for green roof experiments in a tropical environment, the required data treatment to obtain reliable values of rainfall, runoff and evapotranspiration, and how to deal with external disturbances that can influence the experiment results. High resolution rainfall runoff measurements to identify, understand and properly model the relevant runoff processes in a green roof require both tailored equipment and data treatment. A tipping bucket rain gauge is calibrated for and installed to measure minute based rain intensities. A runoff measuring setup is developed that can accurately quantify the runoff up to 6 l/min, and has a high resolution in both time and volume. Two different measuring setups are used to verify the evapotranspiration that is derived from the rainfall and runoff measurements.

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Rapid Detection of Volatile Substances in Water Using a Portable Photoionization Detector

Water Contamination Emergencies ◽

10.1039/9781847552426-00208 ◽

2007 ◽

pp. 208-215

Keyword(s):

Rapid Detection ◽

Volatile Substances ◽

Photoionization Detector

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Influence of the measurement configuration on the results of Raman microspectroscopy of human hair

Quantum Electronics ◽

10.1070/qel17973 ◽

2022 ◽

Vol 52 (1) ◽

pp. 36-41

Author(s):

N N Brandt ◽

E I Travkina ◽

E V Mikhal'chik ◽

A Yu Chikishev

Keyword(s):

Human Hair ◽

Optical Axis ◽

Spectroscopic Studies ◽

Original Method ◽

Raman Microspectroscopy ◽

Measuring Setup ◽

Experimental Facilities ◽

Accuracy Of Measurement ◽

Confocal Raman Microspectroscopy ◽

Chemical Influence

Abstract Increasing interest in spectroscopic studies of human hair raises the question about the accuracy of measurement of their spectra and requires optimisation of experimental facilities. An original method of obtaining transverse hair sections without using a microtome and chemical influence is proposed. The results obtained by confocal Raman microspectroscopy of human hair differently oriented with respect to the optical axis of the measuring setup are compared. It is shown that, in addition to expected changes in the spectra measured at different distances from the hair periphery in the direction to its centre, the spectra measured in the case of hair excitation perpendicular and parallel to its axis are also considerably different.

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