US149176A - Improvement in psychrometers - Google Patents

Description

2 Sheets--Sheet 1. S. F. HU D D LESTON.

.|W l N LUCK 8L l.

Psychrometers.

Patented March 31,1874.

UNITED STATES PATENT FFICE.

JOSEPII IINLOCK, OF CAMBRIDGE, AND JOHN S. F. IIUDDIiESTON, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN PSYCHROMETERS.

Specification forxnirg part of Letters Patent No. 149, [76, dated March 3l, 1874; application filed July 3o, 1873.

To all whom it may concern:

Beit known that we, JosEPrI WrNLooK, ot' Cambridge, in the county ot' Middlesex and State of Massachusetts, and JOI-IN S. F. HUD- DLESTON, ot' Boston, in the county of Suffolk and State aforesaid, have invented an Improved Psychrometrical Indicator, of which the following is a specification:

The object of the present invention is to provide a simple, efficient, and convenient means of determining the relative humidity of the atmosphere or the dew-point, so called, without calculation. The improvements are fully hereinafter described and claimed.

In the accompanying plates of drawings our improved psychometrical indica-tor is illustrated.

In Ilate l, Figure 1 is a face view of the dry and wet bulb thermometers with our indicator adapted thereto; Fig. 2, a transverse horizontal section in plane of line x x, Fig. l. In Plate 2, Fig. 3 is a'plan view of the diagram of figures adapted for the indicator 5 Fig. 4, a view showing both the degrees of saturation and the dew-point of the air.

A and B in the drawings represent, respectivcly, a wet and a dry bulb thermometer, constructed in the usual manner; C, the stl-in g or wicking depending from the muslin surrounding the wet bulb I) of the thermometer A into the water in the cup E; F, a cylinder, adapted to be freely turned by means of a handle or knob, H, in the casing G. The cylinder F is provided with a series of columns of iigures, such as shown in Fig. 3, Plate 2, and these columns are numbered from one (l) to twenty-two (22) inclusive. Each number from one (l) to twenty-two (22) represents the difference bctween the degree of temperature indicated by the dry-bulb thermometer B and the degree indicated by the wet-bulb thermometer A. The iigures of each column of figures are arranged one above another, (see Fig. 3, Plate 2,) and the several figures in each column are the results of calculation, and give, for any degree ofthe wet-bulb thermometer A, the amount of moisture in the air; or, in other words, the degree of saturation of the air, or both the amount of moisture in or the dew-point of the air for any dili'erence between the indica-tions of a wet-bulb thermometer and a dry-bulb thermometer, from one (1) to twenty-two (22) inclusive. The casing serves as a support, in

the present instance, for the two thermometers, as well as for the cylinder, and is secured to the base L. I, the slit or opening. On the left of this slit I, iixed to the casing G, is the scale J, which, in this instance, conforms to the scale of the wet-bulb thermometer. The iigures of the several columns of figures are arranged in parallel horizontal lines, correspondingly to the divisions of the ixed scale J, the number or ligure to be produced as showing the amount of moisture in the air or dew-point being each placed in line horizontally with the degree on the xed scale corresponding to the degree as indicated on the wet-bulb thermometer, in the column of gures having at its head the ligure corresponding to the difference in degrees between the degrees indicated by the readings of the dry and wet bulb thermometers.

To ascertain the moisture in the air, having properly prepared the wet-bulb thermometer, observe the height of the mercury, which, for example, suppose to be 600, and then observe the height of the mercury of dry-bulb thermometer, which, for example, suppose to be 720. Subtract the former, 60, from the latter, 72, and then turn the cylinder until that column of the columns of gures on the cylinder F comes to the casing-slit I, which, in its number, corresponds to the dierence between 6() and r2that is, bring the column marked 12, with red ink, to the slit, and, opposite the line of division marked 60 of the xed scale J observe the number indicated in the said column of figures, which number, 46, is the per centum of moisture in air, as shown at a, Fig. l.

For all degrees of the dry and wet bulb thermometers proceed as above, and the result sought for will be shown by the indicator.

A similar arrangement of indicator may be also adapted by simply a change of figures in the several columns for indicating the dewpoint of the air; or, by a double column of ligures, as shown in Fig. 4, under each division, the indicator may be adapted to show both the dew-point and the degree of saturation; or by t\vo separate cylinders, to be used or operated independently.

As in Fi 4, the left column shovvs the degree of saturation, and the right column the dew-point, and, carrying out the same illustration, in line to the right of 600 on xed scale, and With 4G, the per centum of moisture in the air will be found 3i-the dew-point for the same temperature.

The numbers of the columns, one to tvventy two, are printed in red ink, and the others in black ink, for the purpose of distinction, and of quickly discerning them; but they can all be of the same, or ot' any tivo, colors desired.

rJlhe fixed scale J, instead of corresponding to the ivet-bulb-thermometer scale, can be read as answering` to the dry-bulb thermometer. Of course, the columns of gures relatively so much higher on the scale-that is, the fortysix degrees ascertained, as above-in lieu of being opposite to 60 would then be against or inline of 72; but ive find it better and more convenient to use the Wet-bulb-thermometer scale.

In lieu of having a separate scale for the cylinder, it could be so adapted that the cylinder could revolve in connection with the Wet or dry bulb thermometer scales.

The frame or standard to support the cylinder and thermometer cau be made from any kinds of Woods or metal, and of any form or shape, ornamented as desired.

The cylinder F could revolve horizontally, iu`lieu ot' vertically, as described.

Having thus described our invention, what We claim, and desire to secure by Letters latent, is

The instrument herein described, the saine consisting of the ivet-bulb thermometer A, the dry-bulb thermometer B, the cylinder F, provided Withthe tabulated columns ofiigures, and revolving Within a casing, Gr, having a slit, I, and scale J, all arranged in the relation to each other, substantially as shoivn and described.

' JOSEPH \Y1NL()CK.

JOHN S. F. IIUDDLESTOX.

Witnesses:

EDWIN W. BROWN, J. P. HeELRov.

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