GB2288878A

GB2288878A - Remote Non-Contact Condensation Measurement

Info

Publication number: GB2288878A
Application number: GB9407549A
Authority: GB
Inventors: Fali Minocher Dadachanji
Original assignee: Protimeter PLC
Current assignee: GE Protimeter Ltd
Priority date: 1994-04-15
Filing date: 1994-04-15
Publication date: 1995-11-01
Anticipated expiration: 2014-04-15
Also published as: GB9407549D0; GB2288878B

Abstract

Apparatus for remotely monitoring a surface, for example in a room, to determine the risk of condensation forming on the surface, includes an infra-red pyrometer (C) for sensing the temperature of the surface, humidity or dewpoint sensing means (B) and electrical circuitry receiving signals from the pyrometer and the humidity or dewpoint sensing means and for providing on a display (D) an indication of the magnitude and sense of the difference between the temperature of the remote surface and the sensed or calculated dewpoint. <IMAGE>

Description

DESCRIPTION OF INVENTION Title: "Remote Non-Contact Condensation Measurement" THIS INVENTION relates to the diagnosis of condensation or the likelihood thereof and to apparatus for determining when conditions are such as to produce condensation on a surface, the apparatus using a non-contact form of measurement.

There are many applications in which it is necessary for the occurrence or the likelihood of the occurrence of condensation on surfaces to be monitored, for example in avoiding or rectifying dampness in buildings, or in ensuring that items or materials are stored under conditions such that they will not be subject to deterioration as a result of condensation. Various forms of apparatus for use in such monitoring are known. In some circumstances it is necessary to conduct such monitoring in such a way that the existence of the conditions which will produce condensation, or the approach of such conditions, can be detected before substantial condensation has occurred, because sometimes even conditions of incipient condensation may be sufficient to cause significant damage or deterioration to goods or buildings.In order to detect reliably conditions where condensation is imminent or approaching, it is generally necessary to resort to relatively elaborate and time-consuming testing procedures, requiring a number of separate measurements and comparisons to be made. Typically, in such procedures, the dewpoint temperature of the atmosphere is determined by measuring the ambient temperature and the relative humidity and by using conversion charts to compute the dewpoint temperature, which is then compared with the temperature of the environment to be monitored. Where a surface is being monitored, if the surface temperature is lower than the dewpoint temperature, condensation will be present. The human effort involved in such procedures can be reduced by using automatic apparatus to determine the dewpoint temperature, although such apparatus is generally complex and expensive.

It is an object of the present invention to provide an apparatus for use in determining when conditions are such as to produce condensation, or when such conditions are being approached, and which apparatus can operate when located remotely from the surface or surfaces of interest.

An embodiment of the invention is described below by reference to the accompanying drawing which is a diagrammatic perspective view showing an apparatus embodying the invention, in use.

Referring to the drawing, the apparatus includes a hand-held housing (A) which houses electronic circuitry and carries a display (D), control switches, connector sockets for electronic transducers, etc.

The apparatus further comprises an electronic transducers (B) for measuring air temperature and/or humidity or dewpoint, and also includes a non-contact remote thermometer (C) which can measure the temperature of a surface from a distance and without contact. By way of example, the instrument may have transducers for sensing ambient temperature and atmospheric humidity, and circuitry for deriving from such transducers an electrical signal corresponding to the calculated dewpoint, in manner known per se or may include a chilled mirror system, also known per se, for determining the dew-point directly. The non contact thermometer (C) may, for example, be an industrial infrared pyrometer providing an electrical output signal.

In the arrangement illustrated, the transducer (B) is secured directly to the housing and the non-contact thermometer is a separate component connected by a flexible lead to the measuring instrument (A) via an electrical connector. However, the remote, non-contact thermometer (C) could be incorporated within housing (A) as could the transducer B.

The instrument works as follows: The combination of sensors (B) and instrument (A) calculates the dewpoint of the air at the time of measurement and produces a corresponding electrical signal.

The non-contact thermometer (C) detects the temperature of the surface under investigation remotely and likewise produces a corresponding electrical signal.

The surface temperature and the dewpoint can be compared within the instrument by comparing said electrical signals to produce a "difference" signal. The difference signal representing the difference between the dewpoint and the temperature of the surface to be checked may be applied, possibly after amplification or attenuation, to a centre-zero galvanometer or may be appropriately processed to drive a digital display (D) indicating the value and sign of the difference between the dewpoint and the surface temperature. Using this instrument not only can the existence of the conditions necessary for the occurrence of condensation be detected but this can be done remotely without making contact with the surface being monitored, which may, for example, be a ceiling or overhead girder.

Accordingly, such surfaces can be monitored without recourse to ladders scaffolding, or the like.

It will be appreciated that digital or data processing techniques may be used in the apparatus, so that, for example, the apparatus may calculate the dewpoint and the temperature of the remote surface being monitored in terms of numbers to arrive at a number representing the difference, rather than producing an analog electrical signal corresponding to said difference.

Such a system could be used as a hand-held surveying tool or alternatively fixedly installed at a predetermined location to monitor surfaces continuously for the occurrence of condensation. In the latter case, the instrument, or at least the non-contact thermometer (c) may be mounted on an automatic scanning device to allow a plurality of surfaces in the neighbourhood of the device to be monitored for the occurrence or likelihood of condensation.

Claims

1. Apparatus for use in remotely monitoring a surface to determine the risk of condensation forming thereon, including means for measuring or determining the dewpoint of the atmosphere, means for remotely sensing the temperature of the surface to be monitored and means for comparing the dewpoint temperature and said surface temperature to arrive at an indication of the likelihood or approach of condensation occurring on said surface.

2. Apparatus according to claim 1 wherein said means for remotely sensing temperature comprises an infra-red pyrometer.

3. Apparatus substantially as hereinbefore described with reference to the accompanying drawings.

4. Any novel feature or combination of features described herein.