scispace - formally typeset
Search or ask a question
Journal ArticleDOI

A passive sampler for water vapor

01 Jan 1986-Environment International (Pergamon)-Vol. 12, pp 461-465
TL;DR: In this article, the authors report on improvements made to a passive sampler for water vapor and on the results of tests to determine its suitability for studies of indoor air quality.
About: This article is published in Environment International.The article was published on 1986-01-01 and is currently open access. It has received 5 citations till now.

Summary (1 min read)

Introduction

  • Studies of indoor humidity are important for several reasons.
  • Instrumentation available to measure humidity generally falls into two categories.
  • While they produce detailed information, the cost of the instruments and associated data loggers precludes large scale studies of many indoor environments.
  • These advantages include low cost, ease of deployment, lack of field calibration and maintenance, ruggedness and unobtrusiveness.
  • With both samplers, the weight gain of the sampler and the time of exposure was related to the water vapor concentration sampled.

Linearity, Precision and Accuracy Experiment

  • In a nine-day experiment, seventy-two samplers were exposed to ambient conditions in one of their laboratories while continuously recording ambient temperature and dew point temperature with a LiCl hygrometer (YSI Model 91).
  • Spot checks of humidity were made with fan and sling psychrometers.
  • Atmospheric pressure was monitored in a nearby laboratory.
  • Five blanks (unexposed samplers) were given identical treatment except they were not uncapped.

Blanks Experiment

  • To determine the cause of weight gain of blank samplers, capped samplers and individual sampler components were suspended in a sealed dessicator containing either a Petri dish filled with water or silica gel dessicant.
  • In the case of capped samplers, vacuum grease was applied to various surfaces of the plastic caps and seals to eliminate potential ~leaks.
  • The weight gain or weight loss of samplers and sampler components with time was monitored.

Results and Discussion

  • Instantaneous hourly dew points measured by the LiCl hygrometer in the first experiment were converted to water vapor partial pressures, and the partial pressures were averaged over intervals corresponding to sampler exposures.
  • During the course of the experiment, sampler blanks also gained weight with exposure.
  • While the weight gain was much less than that of the uncapped samplers, it was nonetheless significant, averaging approximately 5 mg over nine days.
  • Attempts to dessicate capped samplers or even.

Did you find this useful? Give us your feedback

Citations
More filters
Journal ArticleDOI
TL;DR: In this article, five types of radon control techniques installed in seven New Jersey houses with basements, systems based on subsurface ventilation (SSV) by depressurization were the most effective and suitable for the long-term reduction of indoor radon levels.

14 citations

Journal ArticleDOI
TL;DR: In this paper, the authors outline important parameters that affect combustion-related indoor air pollution concentrations and exposures, delineates weaknesses in our current understanding of exposures and field sampling methodologies, and mentions important considerations in planning appropriate field sampling strategies.

5 citations

Journal ArticleDOI
TL;DR: In this paper, a simple, inexpensive but reliable passive sampler for estimating monthly averages of relative humidity has been developed, which consists of a 5 ml plastic tube prepared with lithium chloride monohydrate (LiCl. H2O) as trapping medium.
Abstract: As part of the energy and indoor climate survey recently carried out in Sweden (the ELIB study) a simple, inexpensive but reliable passive sampler for estimating monthly averages of relative humidity has been developed. The diffusion sampler consists of a 5 ml plastic tube prepared with lithium chloride monohydrate (LiCl. H2O) as trapping medium. After necessary calibration of this particular design of sampler the relative humidity can be calculated from the weight change of the sampler, the time of sampling and the average temperature during this period. The estimated accuracy of the method is better than k 2% RH up to65% RH.

3 citations

01 Feb 1988
Abstract: .................................................... ............ ix EXECUTIVE SUMMARY .....................................................

3 citations

01 May 1985
TL;DR: One hundred sixteen existing homes were tested and screened for HCHO, NO2, water vapor, and radon using mailed passive samplers as discussed by the authors, and the resulting CO2 concentrations are consistent with a proposed indoor air quality model.
Abstract: One hundred sixteen existing homes were tested and screened for HCHO, NO2, water vapor, and radon using mailed passive samplers. Concentrations ranged up to 136 ppB HCHO, 28 ppB NO2, 9.28 gkg H2O (60% relative humidity at 68F), and 85 pCil Rn. Forty-eight homes with measurable levels of NO2, HCHO, or Rn were selected for more intensive monitoring to evaluate the effects of staged weatherization on pollutant concentrations. Pollutants sampled include: HCHO, NO2, H2O, CO, respirable suspended particles (RSP), and Rn. Meteorlogical monitoring occurred concurrent with leakage area measurements using blower doors and ventilation rate measurements using perfluorocarbon tracers (PFT). A separate controlled study evaluated the interactive effects of air leakage reduction and conductive heat loss reduction on the pollutant levels generated by an unvented combustion heating source. Pollutant concentrations increased after reducing infiltration with house tightening retrofits. Subsequent conductive retrofits reduced heating loads, thereby reducing pollutant generation, and indoor air pollution levels. The resulting CO2 concentrations are consistent with a proposed indoor air quality model. In addition to the study of existing homes, indoor air pollutant screening (Phase I) of Model Conservation Standards (MCS) New Homes and 'typical' New Homes began in January, 1985.
References
More filters
Book
01 Jan 1973
TL;DR: CRC handbook of chemistry and physics, CRC Handbook of Chemistry and Physics, CRC handbook as discussed by the authors, CRC Handbook for Chemistry and Physiology, CRC Handbook for Physics,
Abstract: CRC handbook of chemistry and physics , CRC handbook of chemistry and physics , کتابخانه مرکزی دانشگاه علوم پزشکی تهران

52,268 citations

Journal ArticleDOI
TL;DR: A new type of personal sampler for gases in air, originally reported from this laboratory, has been adapted to measurement of NO2, accurate, light, simple to use and have very good shelf life before and after sampling.
Abstract: A new type of personal sampler for gases in air, originally reported from this laboratory, has been adapted to measurement of NO2. The sampler depends on the transfer of NO2 by diffusion to a triethanolamine coated collector at the sealed end of a tube; the open end of the tube is exposed to the test environment. The devices are accurate, light, simple to use and have very good shelf life before and after sampling.

477 citations

Journal ArticleDOI
TL;DR: A passive sampling unit based on molecular diffusion of the gas to be measured has been designed for use as a personal monitoring device and tested with sulfur dioxide as a means of measuring time-weighted average exposure to this gas.
Abstract: A passive sampling unit based on molecular diffusion of the gas to be measured has been designed for use as a personal monitoring device. To demonstrate the applicability of the approach, the sampler was initially used to measure water vapor concentration in the air; the results showed good accuracy and reproducibility. It was then tested with sulfur dioxide as a means of measuring time-weighted average exposure to this gas. The quantity of gas transferred by diffusion from the environment through an orifice of known dimensions into a chamber maintained at substantially zero concentration by a suitable collecting medium can be used as the basis for calculating average concentration during the time the sampler is in the environment. Calculated and observed values for chamber sulfur dioxide concentrations from 10 ppm to about 0.1 ppm agreed very well over a considerable range of orifice dimensions.

186 citations