IMD Thermometer

Quick Answer: The IMD Thermometer is a meteorological glass thermometer. In Indian catalogue titles the letters IMD usually refer to the India Meteorological Department, and thermometers listed this way follow the patterns used in weather observatories: dry and wet bulb, maximum and minimum. Which of these this listing supplies is confirmed on request.

Thermometers for the Weather Screen

Surface weather observation measures air temperature in a standard way so that readings from different stations can be compared. Thermometers are mounted inside a louvred, white-painted shelter, usually called a Stevenson screen, which keeps off sun and rain while letting air circulate. The India Meteorological Department’s surface observatories use this arrangement, with a set of glass thermometers each doing a different job.

The dry-bulb thermometer gives the current air temperature, and a wet-bulb thermometer beside it, with its bulb in a moist wick, allows humidity to be worked out. The maximum thermometer has a narrow constriction above the bulb that stops the liquid falling back as the air cools, so it holds the day’s highest reading until it is reset by shaking. The minimum thermometer usually contains spirit with a small glass index inside the column; the falling meniscus drags the index down, and it stays at the lowest point reached.

The title does not say which of these types this item is, its scale range or its filling liquid. Tell LabEquip whether you need dry bulb, wet bulb, maximum or minimum thermometers, or a full set for a school weather station. LabEquip also lists a combined maximum and minimum thermometer and a wet and dry bulb hygrometer for simpler set-ups.

Specifications

Care & Handling

• Keep the IMD thermometer inside a ventilated, shaded screen; a thermometer in sunlight reads far above air temperature.
• Reset maximum and minimum thermometers at the same time each day after reading them.
• Read at eye level, with the eye square to the scale, to avoid parallax.
• Store spares horizontally in a padded box and check spirit thermometers for breaks in the column.

Applications

• School and college weather stations recording daily temperatures
• Agricultural meteorology observations at research farms
• Geography practicals on daily temperature range and humidity
• Replacing thermometers in existing Stevenson screens

Why Choose LabEquip

Schools setting up weather stations, agricultural universities and research farms order meteorological thermometers by pattern, often as a set for one screen. LabEquip lists this item in its General Lab Products range; contact LabEquip with the patterns and quantities you need.

Frequently Asked Questions

What does IMD stand for on a thermometer?

In Indian catalogue titles IMD usually refers to the India Meteorological Department, and the thermometer follows the patterns used at weather observatories. Confirm the exact pattern with LabEquip, as the title does not state it.

How does a maximum thermometer hold its reading?

It has a narrow constriction just above the bulb. As the air cools, the liquid column breaks at the constriction instead of flowing back, so the top of the column stays at the highest temperature until the thermometer is shaken to reset it.

How does a minimum thermometer work?

It usually contains spirit with a small glass index inside the column. When the temperature falls, the surface of the spirit drags the index down; when it rises, the spirit flows past the index, which stays at the lowest point reached.

Why must weather thermometers be kept in a screen?

Sunlight, rain and heat from nearby surfaces make a thermometer read its own heating rather than the air temperature. A louvred, white screen shades it while letting air move freely around it.

At what time should readings be taken?

At fixed times each day, as used by the station, so records are comparable. Maximum and minimum thermometers are read and reset once a day at the same time.

Can students use these thermometers?

Yes, with care. They are glass instruments, so students should read them in place in the screen and leave resetting and handling to a trained person.

Last Updated: September 2026