Thermo-Hygrometer, Digital

Quick Answer: The Thermo-Hygrometer, Digital is an electronic meter that shows room air temperature and relative humidity (RH) side by side on one screen. A digital thermo-hygrometer is used to watch storage and working conditions in rooms where damp or heat can spoil chemicals, optics, samples or records.

Two Readings That Explain Most Storage Problems

Relative humidity expresses how close the air is to saturation: the water vapour present, as a percentage of what air at that temperature could carry. Because warm air can hold more, RH and temperature have to be read together to make sense of either. In a humid monsoon month a storeroom can stay warm while RH climbs high enough for hygroscopic salts to cake, paper labels to curl and mould to grow on leather cases and microscope lenses.

Instruments of this type generally use a small electronic humidity sensor beside a temperature sensor, so readings appear continuously and without the wet-wick upkeep of a sling psychrometer. Place it at working height, away from windows, air-conditioner outlets and walls that catch the sun, and let it settle after moving it between rooms. Whether this model also stores minimum and maximum values, shows dew point or has a remote probe is not stated in the title.

Related models with extra functions are listed as digital thermo-hygrometers; choose between them by the features you need to record. This unit covers the everyday need of a single room reading.

Applications

• Monitoring chemical stores where hygroscopic reagents absorb moisture
• Protecting microscopes and optical instruments from fungus in humid seasons
• Keeping conditions steady in balance rooms and sample-weighing areas
• Recording storage conditions in seed banks, herbaria and archive rooms

Specifications

Care & Handling

• Keep the sensor openings free of dust, and never spray cleaning liquid onto the case.
• Do not place the digital thermo-hygrometer on a window sill, above a radiator or in an air-conditioner’s air stream.
• Replace the battery when the display fades.
• Compare it occasionally with a psychrometer or a reference hygrometer.

Why Choose LabEquip

Laboratory managers, school science stores, museums and seed banks buy this instrument to show that storage conditions are under control. LabEquip lists this model in General Lab Products; ask about memory and display features through the contact page.

Frequently Asked Questions

What relative humidity suits a chemical store?

Aim for dry, stable conditions, and follow the storage requirements on each chemical’s label or safety data sheet. A rising humidity trend is a signal to look at ventilation or dehumidification, especially where hygroscopic or water-reactive substances are kept.

Why does the humidity reading change when I move the instrument?

RH depends on temperature. Carrying the instrument from a cool room to a warm one changes both readings, and the sensors need time to settle. Wait until the values stop changing before recording them.

How is it different from a wet and dry bulb hygrometer?

A wet and dry bulb instrument works out RH from two thermometer readings and a table, and needs its wick kept wet. The digital thermo-hygrometer shows RH directly, which is quicker for routine checks, while the psychrometric method is useful for teaching and cross-checking.

Can it be used outdoors?

Only if protected from rain and direct sun, for example inside a ventilated weather screen. Sunshine heats the case and gives temperatures that are too high.

Why do microscopes need humidity monitoring?

Persistent high humidity allows fungus to grow on lenses and prisms, which etches coatings and cannot always be cleaned away. Keeping instrument rooms dry, with desiccant in storage cabinets, helps prevent it.

How can I check the humidity reading?

Compare it with a sling psychrometer used in the same room at the same time. Salt-solution checks are also used, but a side-by-side comparison is the simplest routine check.

Last Updated: September 2026