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.
|Published (Last):||5 March 2015|
|PDF File Size:||10.47 Mb|
|ePub File Size:||8.96 Mb|
|Price:||Free* [*Free Regsitration Required]|
The Electronic Dewpoint Meters can be placed in the humidity chamber and the measurements monitored using the data output feature to achieve calibration against another relative humidity gauge that is separately calibrated for trace-ability.
This standard is also available to be included in Standards Subscriptions.
The output from this sensor is displayed as Ta. As the voice of the U.
ASTM E337 – 15
Figure 4 The Electronic Dewmeter with an external thermocouple sensor connected. Our office will be closed from December 21st until January 2nd 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. 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.
Please first verify your email before subscribing to alerts. You may delete a document from your Alert Profile at any time. Historical Version s – view previous versions of standard. We wish you and yours a Happy Holiday Season! Adjusting the logging interval can be done via the screen shown when interval logging is first selected. The value of the Dewpoint Temperature mainly depends on the Relative Humidity of the air, that is the volume of moisture contained in the air at a given temperature compared to the maximum volume of moisture that this volume of air could contain if it were saturated at that temperature.
Recent Developments in the Measurement and Monitoring of Climatic Conditions
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 extra resolution provided by the electronic gauge over that of the whirling and sling hygrometers is useful in reports. Note — Ta will be the same value as Tdb. Online orders will ship e3377 January 2, The feature in the electronic Dewmeter that displays the calculated wet bulb temperature and the measured dry bulb temperature the air temperature, Ta has good agreement with the wet and dry bulb method in conditions of stable relative humidity.
The wireless connection will operate over a distance of up to 15 m. This paper describes the latest design and operational features of a digital dewpoint meter and describes how this gauge is calibrated and ast, for both quality control of paint application processes and for monitoring cure conditions using data logging techniques. If contamination is present it can lead to the formation of a corrosion cell and to premature failure of the coating.
Please sign into an account with a subscription to this content, or email for help at support madcad.
Add to Alert PDF. You can download and open this file to your own computer but DRM prevents opening this file on another computer, including a networked server.
Please e373 our new address: The air temperature is measured using another semiconductor sensor mounted close to the RH sensor to minimize any differences in conditions. The default time is 1 minute.
This arrangement is shown in figure 5. Are you sure e373 want to empty the cart? Your Alert Profile lists the documents that will be monitored. 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.
Please first log in with a verified email before subscribing to alerts.
It is critical to the service life of a protective coating system that the coating is applied to a clean, dry surface, in order to ensure that contamination is not trapped within the system either between the primer coating and the substrate or between subsequent layers that make up the full protective system. Calibration of the Electronic Dewpoint Meter is carried out in a temperature controlled humidity chamber, whereas the calibration of the wet and dry bulb hygrometers is limited to assessing the accuracy of the spirit in glass thermometers.
The definition of the Dewpoint Temperature is the temperature at which moisture will condense from a body of air at a higher temperature.
We have no amendments or corrections for this 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 preset interval can be adjusted from 1 second to 1 hour. No further reproductions authorized.
It is therefore essential that the awtm humidity RHthe air temperature Ta and the surface temperature Ts are measured quickly and accurately so that the dewpoint temperature Td and the difference between the surface and dewpoint temperatures can be calculated for correct paint or not paint decisions to r337 made.
Register for a trial account. Only the essential features of the psychrometer are specified.
There are astmm operational aspects of the wet and dry bulb hygrometer method for measuring humidity that influence the accuracy of the measurement including insufficient whirling so steady-state conditions are not reached, contamination of the water so optimum evaporation astk for the wet bulb are not achieved, the use of spirit-in-glass thermometer in place of the environmentally unsound mercury-in-glass thermometers.
The external thermocouple is also attached to the substrate using a magnet to get a good thermal contact for the surface temperature measurement. Figure 3 — Digital Electronic Dewpoint Meter. Mercury, or its vapor, has been demonstrated to be hazardous to health and corrosive to materials. However, the hygrometers described in this method use mercury in glass thermometers, which are asrm longer acceptable under Restriction of Hazardous Substances RoHS legislation round the world.
The Dewmeter gauge displays the parameters to one decimal place. E3337 humidity gauges have been available for some years but there is now a Dewpoint Meter that is designed specifically to monitor the paint process and that also provides a method for recording and presenting data as proof of the conditions prevailing.
For more specific safety precautionary statements, see 8.