Special care should always be taken to keep the instruments clean. This not only enhances their performance but also lengthens their useful life and improves their appearance.
Shifting of Met Instruments
Any permanent shift / change of the observatory or any instrument particularly the barometer must be intimated to the C Met O, and JD Met (E) and also to be annotated in the current weather register. Instruments are to be shifted (particularly barometer) only under strict supervision of the met officers. Where Met Officers are not available, the controlling command is to detail a met officer to supervise the shifting of observatory and mercury barometer.
The following points are to be noted while carrying out the general inspection of met observatory.
(a) Observatory must be checked and the instrument compared with standard at least once in two year.
(b) It is to be ensured that exposure conditions are not disturbed due to new constructions or trees.
(c) New correction if found after comparison to be brought into affect, only after Air HQ approval.
Maintenance of Met Instruments
There are few general principles to be kept in mind for maintenance of Met Instruments. They are as follows:
(a) Avoid the use of cleaning material of a corrosive or clogging nature.
(b) Use clock oil of good quality as a lubricant. Apply it sparingly only to bearings where it is needed and remove surplus oil.
(c) Do not defer cleaning operation till the instrument has reached a condition of neglect which prevents its working properly. Cleaning should be done regularly.
The following special features to be born in mind while carrying out the maintenance of met instruments:
(a) Plain Brass or Copper Parts: This may be kept bright by the use of oily rag or by metal polish.
(b) Lacquered Brass or Copper Parts: Clean with soft chamois leather. No polish should be applied.
(c) Polish Wood Work: Clean with soft chamois leather. Rub on a little linseed oil with a soft cloth if necessary.
(d) Glass and Porcelain: Clean off dirt with a moist rag or chamois leather.
(e) Bearings and Pinions Hinges: Lubricate as necessary with a touch of clock oil.
(f) Painted Wood Work: In dusty localities wood work should be brushed periodically or cleaning with soap water once in a month.
(g) Painted Surfaces Liable to Inking: Remove ink while it is wet, with a damp cloth. Oil stains should be removed by the application of a small quantity of soap water applied with a damp cloth. Ethylated spirit may also be used.
Maintenance and Regular Checks / Precautions
(a) Ensure proper supply and earthing to the systems which includes all modern met equipment, AWS etc.
Recommended supply voltage : 240 V AC, 50 Hz
Safety limit/High limit : 255 ± 5V AC
Low limit : 190 ± 5V AC
(b) If the supply is frequently beyond the high or low limit, in order to avoid shut down, the user should make his own arrangement to stabilize the supply.
(c) Protect the anemometer and wind vane cable properly to avoid accidental damage. Ensure that any joints in the cable are properly insulated.
(d) Lubricate the instrument regularly by referring the instructions for lubrication. Special care is to be taken on sites near sea shore. The frequency of lubrication may be increased if desired to avoid rusting of bearing due to salty weather.
(e) Take care that the delicate parts of the instrument such as bearings, starter coil etc are not damaged when the instrument is dismantled for maintenance.