ASTM E Standard Test Method for Measuring Humidity with a Psychrometer (the Measurement of Wet- and Dry-Bulb Temperatures). Find the most up-to-date version of ASTM E at Engineering ASTM-Epdf – Download as PDF File .pdf), Text File .txt) or read online.
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Only the essential features of the psychrometer are specified. The preset interval can be adjusted from 1 second to 1 hour. Online orders will ship on January 2, Using the electronic Dewmeter Gauges ensures that changes in the microclimate that can exist in enclosed areas can easily be recognized and the data-logging feature means that an accurate record for the duration of a process, either the application of the paint or the subsequent cure process, can be made.
As the voice of the U. Enter your account email address to request a password reset: Need more than one copy? These errors accumulate from a number of operational issues such as alignment of the lens in the glass thermometers for optimum position when reading both thermometers, parallax errors when reading the position of the thread relative to the scale on the glass, heat from hands transmitted to the bulbs of the thermometers and resolution of the measurement and the conversion of the readings to rh and dewpoint.
Recent Developments in the Measurement and Monitoring of Climatic Conditions
The traditional method of evaluating the climatic conditions for painting has significant limitations in practise due to the time taken to obtain readings and the potential errors of these readings. Our office will be closed from December 21st until January 2nd Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. The Dewpoint Temperature is then compared to the temperature of the surface to be painted determined by another measurement, sometimes using a magnetic bi-metallic strip thermometer.
The external thermocouple is also attached to the substrate using a magnet to get a good thermal contact for the surface temperature measurement. The advantages of the Electronic Dewpoint Meter are in the speed and accuracy of the measurement and in the traceability of the gauge calibration to a national standard. No other units of measurement are included in this standard.
Figure 3 — Digital Electronic Dewpoint Meter It can clearly be seen that if a surface is cooled sufficiently the surrounding air will eventually give up its moisture to the cool surface.
Standards Subsctiption may be the perfect solution. Please sign into an account with a subscription to this content, or email for help at support madcad. Guidance on the estimation of the probability of condensation prior to paint application.
Search book title Enter keywords for book title search. Figure 3 — Digital Electronic Dewpoint Meter.
ASTM E337 – 15
asfm The right to access the electronic files of ASTM Standards is for purposes of viewing for individual use only. No items in cart. To simulate the practical operation of the Dewmeter, the calibration is carried out at low and high values of RH, with low and high values of Ta. Measurement of relative humidity in controlled conditions is not practical for the whirling or sling hygrometer as the presence of an operator in the controlled environment causes errors.
However, the extra resolution provided by the electronic gauge over satm of the whirling and asm hygrometers is useful in reports. This arrangement is shown in figure 5. The PC version of the software also offers features for analyzing data, for reporting and for archiving date for future analysis or comparison.
It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. However, the hygrometers described in this method use mercury in glass thermometers, which are no longer acceptable under Restriction of Hazardous Substances RoHS legislation round the world. Examples of these measurement devices are shown in figures 1 and 2 below. Caution should be taken when handling mercury and mercury containing products.
The practicality of field calibration checks using saturated salt solutions to provide reference values for RH measurement is being investigated. F337 1 shows the typical measured reference values e373 these parameters that appear on the calibration certificate.
In addition the electronic files may not be downloaded or distributed elsewhere over computer networks or otherwise. Surface temperature measurements are also made at low and high values and the external temperature measurement is checked at four values across the range.
No other units of measurement are included in this standard. Link to Active This link will always route to the current Active version of the standard. Historical Version s – view previous versions of standard. The estimated values for the wet bulb temperature Twb and the dry bulb temperature Tdb can be displayed by selecting these parameters from the Display menu in preference to two of the usual set, e. The surface temperature is measured either using an integrated K-type thermocouple sensor mounted next to the RH and Air Temperature sensors or by using an optional external thermocouple sensor connected via a K-Type connector.
The method specified is based on measuring air temperature and relative humidity, calculating the dewpoint temperature, measuring the steel surface temperature, and estimating the minimum surface temperature above the dewpoint temperature that is needed to avoid condensation under the prevailing environmental conditions. Please first verify your email before subscribing to alerts.
Figure 4 The Electronic Dewmeter with an external thermocouple sensor connected. Figure 5 — Dewpoint Meter Configured for Data-Logging Data can be recorded using two methods, user activated recording of values as and when required or the data-logging mode, with reading sets recorded automatically at the end of the pre-set interval.