Disclosure to Promote the Right To Information

Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.

इंटरनेट मानक

“!ान $ एक न' भारत का +नम-ण”Satyanarayan Gangaram Pitroda

“Invent a New India Using Knowledge”

“प0रा1 को छोड न' 5 तरफ”Jawaharlal Nehru

“Step Out From the Old to the New”

“जान1 का अ+धकार, जी1 का अ+धकार”Mazdoor Kisan Shakti Sangathan

“The Right to Information, The Right to Live”

“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता है”Bhartṛhari—Nītiśatakam

“Knowledge is such a treasure which cannot be stolen”

“Invent a New India Using Knowledge”

है”ह”ह

IS 5725 (1970): Psychrometers, unventilated (dry and wetbulb hygrometers) [CHD 10: Glassware]

IS : 5725 - 1970

Indian Standard SPECIFICATION FOR

PSYCHROMETER& UNVENTILATED (DRY AND WET BULB HYGROMETERS)

Laboratory Glassware and Related Apparatus Sectional Committee,

6

CDC 33 Chairman Representing

*DRYS. R. LELE Borosil Glass Works Ltd, Bombay

Members SWRI K. L. BANERJEE National Test House, Calcutta COL A. K. B~su Directorate General of Armed Forces Medical

Services Ministry of Defence ) SHRI S. C. CHAKRABORTY Chemical an 6

Board ) Metallurgical Laboratory ( Railway

SHRI B. K. SHENOY ( Alternate ) SHRI P. P. CHANDRA Seraikella Glass Works Pvt Ltd, Kandra

SHRI S. C. VARSHNEI ( Alternate ) SHRI M. K. CHITRE Development Commissioner, Small Scale Industries,

New Delhi SHRI HARI DATTA The Ganga Glass Works Pvt Ltd, Balawali DR N. K. DUTTA Haffkine Institute, Bombay

SHRI Y. S. NIMBKAR ( Alternate ) SHRI S. R. KHANNA Directorate General of Technical Development,

New Delhi DR S. KUMAR Central Glass and Ceramic Research Institute

( CSIR ), Calcutta DR S. C. NIYOCI The Scientific Indian Glass Co Ltd, Calcutta

SHRI A. SIRCAR ( Alternate ) SHRI PREM PRAKASH National Physical Laboratory ( CSIR ), New Delhi

SHRI MOHINDER NATH ( Alternate) SHRI K. V. RAMACHANDRAN Ministry of Defence ( R & D ) SHRI N. RANGASWAMY Glaxo Laboratories ( India ) Pvt Ltd, Bombay

, SHRI D. C. ROY National Instruments Ltd, Calcutta SHRI SANTOKH SINGH National Chemical Industries, New Delhi

SHRI PRITHIPAL SINGH ( Alternate ) SHRI P. G. TULPULE Indian Council of Medical Research, New Delhi SHRI D. DAS GUPTA, Director General, IS1 ( Ex-o@cio Member )

Director ( Chem ) Secretary

SHRI G. P. SARASWAT Assistant Director ( Chem ), IS1

( Continued on Page 2 )

*Miss A.M. Mani succeeded Dr S.R. Lele as chairman after the finalization of the draft standard.

I~NDIAN STANDARDS INSTITUTION MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG

NEW DELHI 1

1s : 5725 - 1970

( Continued from page 1 )

Thermometers Subcommittee, CDC 33 : 2

Convener Representing

SHRI T. D. BANSAL National Physical Laboratory ( CSIR ), New Delhi

Members SHRI H. K. BANERJEE National Instruments Ltd, Calcutta

Srnu J. SANYAL ( Alternate ) SHRI K. L. BANERJEE National Test House, Calcutta SHRI HARI DATTA . The Ganga Glass Works Pvt Ltd, Balawali SHRI A. N. DIXIT Ministry of Defence ( R & D ) SHRI K. GANGAYYA Directorate General Health Services, New Delhi t/ SHRI DEEPAK R. KOTHARI Jintan Clinical Thermometers Co (India ) Private

Ltd, Surendranagar ( Gujrat ) SHRI R. K. KOTHARI (Alternate)

SHRI V. KRISHNAMOORTHY Directorate General of Technical Development, New Delhi

Mrss A. M. MANI India Meteorological Department, New Delhi SHRI S. GOPINATH ( Alternate )

SHRI Y. D. SHARMA Dutta Scientific Works, Solan

2

IS:5725 -1970

Indian Standard SPECIFICATION FOR

PSYCHROMETERS, UNVENTILATED ( DRY AND WET BULB HYGROMETERS)

c \ 0. FOREWORD

0.1 This Indian Standard was adopted by the Indian Standards Institu- tion on 21 April 1970, after the draft finalized by the Laboratory Glass- ware and Related Apparatus Sectional Committee had been approved by the Chemical Division Council.

0.2 Psychrometers, which are also known as dry and wet bulb hygrometers and curometers, unventilated, are used for measuring atmospheric humidity ( relative humidity ) for agricultural, commercial and industrial purposes. They consist of two similar liquid-in-glass thermometers exposed side by side, the bulb of one of which is covered with a piece of wet fabric and allowed to cool by natural free evaporation. Relative humidity is computed from the readings of these two thermometers by the use of psychrometric tables.

0.3 This standard has clause 5.2 which provides for agreement between the purchaser and the supplier.

0.4 For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, express- ing the result of a test, shall be rounded off in accordance with IS : 2-1960*. The number of significant places retained in the rounded off value should

\ i be the same as that of the specified value in this standard.

1. SCOPE

1.1 This standard prescribes the requirements and methods of sampling and test for unventilated psychrometers.

2. TERMINOLOGY

2.1 For the purpose of this standard,-the definitions given in IS : 2627-1963t

shall apply.

*Rules for rounding off numerical values ( revised ). TGlossary of terms relating to liquid-in-glass thermometers,

3

.-

IS : 5725 - 1970

3. GRADES

3.1 -Psychrometer-s shall be of two grades, namely:

a) Grade A for normal day-to-day use, and b) Grade B for industrial use.

4. REQUIREMENTS

4 .O General - Psychrometers shall consist of a pair- of dry and wet bulb thermometers mounted in a frame. The wet bulb thermometer shall be

I 215:

lNlf3 TO REAR SIDE/

GRADE A GRADE B

All dimensions in millimetres.

FIG, 1 TEERW~YETEW FOR UNVENTILATID PSYCYFCOVEQJQ

4

IS : 5725 -1970

provided with a water reservoir, a muslin bag and wick arrangement for wetting the fabric, covering the wet bulb.

4.1 Thermometers

4.1.1 Dry and wet bulb thermometers for Grade A psychrometers shall have a range from -10 to +55”C subdivided into 0.5% (see Fig. 1 ). The bulb shall be spherical with an outside diameter IO.0 f 1.5 mm.

4.1.2 Dry and wet bulb thermometers for Grade B psychrometers shall have a range 0 to 100°C subdivided into 0*5”C (see Fig. 1 ). 1The bulb

c

shall be spherical with an outside diameter of 10-O f I.5 mm.

‘I 4.1.3 The graduation lines on both the thermometers, when fixed in position, shall match to within half the smallest division of the thermo- meters at all points on the scale engraved or marked on the mount.

4.2 Muslin and Wick -A piece of thin, clean, water-absorbing muslin, just sufficient to cover the bulb, shall be stretched smooth over the bulb creases being avoided as far as possible. It shah be washed with soap and water and dried before use. Only a single thickness shall be used. The muslin shall be kept in place by attaching the cotton wick (see Fig. 2 ), and the wick shall dip in the small reservoir below.

FIQ. 2 MUSLIN AND

5

WCK

18:5725-1970

DRY ? WET

. ,

FIG. 3 THERMOMFTERS AND WATER RESERVOIR FJBE;D OF MQUN~

6

1s : 5725 - 1970

4.3 Water Reservoir - The water reservoir shall be made of glass, plas- tics, glazed porcelain or any other non-corrodible metal, with a narrow opening not exceeding 10 mm in diameter. The reservoir for Grade A psychrometers shall have a nominal capacity of 50 ml and for Grade B psychrometers, 100 ml.

4.4 Mount - The two thermometers and the water reservoir of an instru- ment shall be fixed on a mount; the axes of thermometers being at least 3.5 cm apart. A suitable illustration is provided in Fig. 3.

. c5

MARKING AND PACKXNG

5.1 Marking - Psychrometers shall be engraved on the mount with the following information:

a) The letter ‘ “C ’ near the top of each thermometer;

b) Type of psychrometer; and c) Maker’s name or recognized trade-mark, if any,

5.1.1 Psychrometers may also be marked with the IS1 Certification Mark.

NOTE -The use of the IS1 Certification Mark is governed by the provisions of the Indian Standards Institution ( Certification Marks ) Act, and the Rules and Regulations made thereunder. Presence of this mark on products covered by an Indian Standard conveys the assurance that they have been produced to comply with the requirements of that standard, under a well-defined system of inspection, testing and quality control during production. This system, which is devised and supervised by IS1 and operated by the producer, has the further safeguard that the products as actually marketed are continuously checked by IS1 for conformity to the standard. Details of conditions, under which a licence for the use of the IS1 Certification Mark may be granted to manufacturers or processors, may be obtained from the Indian Standards Institution.

5.2 Packing - Every instrument shall be packed in a suitable cardboard carton or as agreed to between the purchaser and the supplier.

6. SAMPLING AND INSPECTION

6.1 Lot - All psychrometers belonging to the same grade and consign- ment shall constitute a lot.

6.2 All the glass thermometers shall be tested for all requirements prescribed in IS : 2480-1964” in addition to those prescribed in this standard.

6.3 Five percent pieces of the lot shall be tested for the requirements of the mount.

*Specification for general purpose glass thermometers,

7

INDIAN STANDARDS

IS:

878-1956

915-1958

1117-1958

1381-1959

1388-1959

1541-1959

1574-1960

1575-1960

1590-1960

1672-1967

1996-1962

1997-1967

2480-1964

2618-1963

2619-1963

2620-1963

2626-1963

2627-1963

3055-1965

3104-1965

3608-1966

4161-1967

4162-1967

4426-1967

4529-1968

4610-1968

4825-1968

5165-1969

5717-1970

5725-1970

ON

Laboratory Glassware

Specification for graduated measuring cylinders

Specification for one-mark graduated flasks . . .

Specification for one-mark pipettes . . . . . .

Specification for boiling flasks ( narrow-necked )

Specification for reagent bottles . . . . . .

Specification for glass filter funnels . . . . . . Specification for glass weighing bottles . . .

Specification for separating funnels . . . . . . Specification for glass filter flasks . . . . . .

. . .

. . .

. . . . . . . . . . . . . . . . . . . . .

Specification for floating dairy thermometers (Jirst revision )

Specification for glass stopcocks . . . . . . . . .

Specification for burettes (&t revision ) . . . . . .

Specification for general purpose glass thermometers . . . Specification for test-tubes . . . . . . . . .

Specification for glass beakers . . . . . . . . . Specification for distilling flasks . . . . . . . . . Specification for Petri dishes . . . . . . . . .

Glossary of terms relating to liquid-in-glass thermometers

Specification for clinical thermometers . . . . . . Specification for density hydrometers . . . . . . Specification for glass alcoholometers . . . . . . Specification for Nessler cylinders . . . . . . . . . Specification for graduated pipettes . . . . . . . . .

. . .

. . .

. . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..* . . . . . .

1..

Methods of sampling laboratory glassware and medical glass

instruments . . . .,. . . . . . . . . . . . . Specification for glass tubes for medical thermometers . . . . . .

Specification for glass tubes for general purpose and reference

thermometers . . . . . . . . . . . . . . . . . . Specification for laboratory and reference thermometers . . .

Specification for interchangeable conical ground glass joints

Specification for Pyknometers . . . . . . . . . . . .

Specification for psychrometers, unventilated ( dry and wet bulb

hygrometers ) . . . . . . . . . . . . . . . . . .

RS

l-50

1.50

2.00

2.50

2.50 i -‘, 2.00 ‘1 d’

2.00

2.50

2.50

3.50

300

5.00

2’00

2.00

2.50

2.00

2.00

1.00

3.00

4.00

2.50

2.50

5.00

2.50

3.50 ’ ’

3.50

3.50

3.50 -

2.50