Description

Introduction Zeal Wet and Dry Hygrometer 

The Hygrometer Thermometer Wet and Dry Bulb stands as one of the most reliable and scientifically proven tools for accurate humidity and temperature measurement. Zeal Wet and Dry Hygrometer Alcohol Base Professionals across Bangladesh trust this classic psychrometric instrument to deliver precise relative humidity, dew point,  and wet-bulb depression readings without the need for electronic sensors or batteries. Zeal Wet and Dry Hygrometer Alcohol Base

Specifications Zeal Wet and Dry Hygrometer

Parameter	Specification
Instrument Type	Wet and Dry Bulb Psychrometer / Hygrometer Thermometer
Measurement Parameters	Dry-Bulb Temperature, Wet-Bulb Temperature, Relative Humidity (%RH), Wet-Bulb Depression, Dew Point Temperature
Temperature Range	–10°C to +50°C (14°F to 122°F)
Temperature Scale	Celsius (°C) and Fahrenheit (°F) dual scale
Temperature Graduation	1°C / 2°F per division
Temperature Accuracy	±1°C (±2°F)
Relative Humidity Range	10% RH to 100% RH
RH Determination Method	Psychrometric table (printed on instrument board)
RH Resolution	1% RH (via table interpolation)
Thermometer Type	Glass-tube spirit (red) or mercury thermometer
Wet Bulb Wick Material	Cotton muslin sleeve / wick
Wick Water Reservoir	Integrated water reservoir trough or external wick cup
Mounting Board Material	ABS plastic or anodised aluminium alloy
Mounting Method	Wall-mount screws or free-standing base (model dependent)
Instrument Dimensions	Approx. 300 mm × 80 mm × 15 mm (L×W×D)
Thermometer Length	Approx. 270 mm per thermometer
Weight	Approx. 180 g (complete assembly)
Operating Temperature	–10°C to +50°C
Operating Humidity	10% – 100% RH
Storage Temperature	–20°C to +60°C
Power Requirement	None – fully passive instrument
Calibration	Factory-calibrated; optional traceable calibration certificate available
Standards Compliance	Meets WMO Guide to Meteorological Instruments (WMO-No. 8) reference instrument guidelines
Colour	White board with red (or blue) spirit thermometers
Psychrometric Table	Printed on instrument board; covers 0°C–50°C dry bulb, 0–15°C depression range
Replacement Wick	Available separately
Warranty	1 Year Official Warranty (ASTZ Bangladesh)
In the Box	Wet and dry bulb thermometer assembly, cotton wick/sleeve, water trough or reservoir, mounting screws, psychrometric reference chart, user guide

 

Key Features Zeal Wet and Dry Hygrometer 

1. Dual Thermometer Design – Two calibrated thermometers measure dry-bulb and wet-bulb temperatures simultaneously for complete psychrometric data.
2. Built-in Psychrometric Table – The printed humidity lookup chart on the instrument board allows instant relative humidity determination with zero calculation effort.
3. Battery-Free Operation – The instrument requires no power source, making it ideal for remote locations, fieldwork, and areas with unreliable electricity.
4. Wide Temperature Range – Measures from –10°C to +50°C (or equivalent Fahrenheit), covering most ambient environmental conditions.
5. High Measurement Accuracy – Calibrated glass thermometers deliver ±1°C accuracy, suitable for professional laboratory and industrial reference use.
6. Cotton Wick Wet Bulb System – The replaceable cotton wick keeps the wet-bulb sensor consistently moistened for stable and reproducible readings.
7. Dual Scale (°C / °F) – Many models feature both Celsius and Fahrenheit graduations for international compatibility and ease of cross-referencing.
8. Durable Rigid Mounting Board – The aluminium or ABS plastic backing board allows secure wall mounting or stand placement in fixed monitoring stations.
9. Corrosion-Resistant Construction – Glass thermometer tubes and non-corroding board material ensure a long service life in humid or industrial environments.
10. Traceable Calibration – Available with factory calibration certificate, meeting requirements for ISO-compliant laboratories and quality-management systems.

Applications Zeal Wet and Dry Hygrometer 

The Hygrometer Thermometer Wet and Dry Bulb serves critical roles across a diverse range of industries and settings:

1. Meteorology & Weather Stations – Provides standard surface humidity observations for national weather networks, airport weather reporting, and research stations.
2. Greenhouse & Horticulture – Monitors relative humidity and temperature at canopy level to optimise plant growth, prevent fungal disease, and control irrigation schedules.
3. HVAC Design & Commissioning – Supplies psychrometric data for air-handling unit sizing, coil selection, cooling tower design, and duct leakage testing.
4. Pharmaceutical & Food Processing – Validates clean-room and storage humidity compliance with GMP, FDA, and WHO guidelines.
5. Textile Mills & Garment Factories – Controls loom-room humidity to prevent yarn breakage, static build-up, and fabric quality defects — especially critical in Bangladesh’s RMG sector.
6. Tobacco & Tea Processing – Maintains precise humidity levels during curing, drying, and storage to preserve product quality and aroma.
7. Museum & Archive Conservation – Monitors humidity to protect artefacts, paintings, manuscripts, and rare books from moisture damage and mould.
8. Building & Construction – Assesses ambient humidity during concrete curing, paint application, wood installation, and waterproofing works.
9. Educational Laboratories – Teaches psychrometry, atmospheric science, and heat transfer concepts in university and polytechnic institutes.

 

Who Uses This 

Professionals and institutions across Bangladesh and beyond rely on the wet and dry bulb hygrometer thermometer for daily measurements:

1. Meteorologists & Weather Observers – For standard surface synoptic observations and climate monitoring networks.
2. HVAC Engineers & Technicians – To perform psychrometric calculations during system design, commissioning, and fault diagnosis.
3. Greenhouse & Farm Managers – To maintain crop-specific humidity conditions and prevent post-harvest losses.
4. Quality Control Managers in Garment & Textile Industries – To ensure loom-room and fabric-storage humidity meets production specifications.
5. Pharmaceutical & Food Safety Officers – To demonstrate humidity compliance with regulatory and audit requirements.
6. Museum Curators & Archivists – To protect irreplaceable collections from humidity-related deterioration.
7. University & College Lecturers and Students – For thermodynamics, environmental science, and atmospheric physics laboratory exercises.
8. Construction & Civil Engineers – To validate ambient conditions before concrete pours, coatings, and adhesive applications.

 

Frequently Asked Questions (FAQ)

Q: What does the Hygrometer Thermometer Wet and Dry Bulb measure?

A: It measures dry-bulb temperature, wet-bulb temperature, relative humidity (%RH), wet-bulb depression, and dew point temperature. Users read the two thermometer values and then consult the built-in psychrometric table to determine relative humidity and other parameters without any calculations or digital devices.

Q: How does the wet and dry bulb thermometer work?

A: The instrument uses two identical thermometers. The dry-bulb thermometer measures ambient air temperature freely. The wet-bulb thermometer wraps its sensing bulb in a damp cotton wick connected to a water reservoir. Evaporation from the wick cools the wet-bulb thermometer below the dry-bulb reading. The difference — the wet-bulb depression — directly indicates relative humidity when cross-referenced with the psychrometric chart.

Q: Does the wet and dry bulb hygrometer need batteries or power?

A: No. The Hygrometer Thermometer Wet and Dry Bulb operates completely passively. It needs no batteries, no electronic components, and no external power source. This makes it exceptionally reliable for continuous monitoring in remote installations, field surveys, and locations where electrical power is unavailable or unreliable.

Q: How accurate is the wet and dry bulb hygrometer thermometer?

A: Each calibrated glass thermometer delivers ±1°C temperature accuracy. The resulting relative humidity accuracy depends on accurate temperature reading and correct table interpolation; typical RH accuracy ranges from ±3–5% RH under controlled conditions. For the highest accuracy, keep the wick clean, use distilled water, and ensure adequate air circulation around both thermometers.

Q: How often does the wet bulb wick need replacement?

A: Replace the cotton wick every 1–3 months under regular use, or sooner if it shows discolouration, mineral deposits, or stiffening. A clean, fully saturated wick ensures evaporative cooling occurs correctly and maintains measurement accuracy. ASTZ Bangladesh stocks replacement wicks for all standard models.

Q: Can I use tap water in the wet bulb reservoir?

A: Use distilled or deionised water whenever possible. Tap water contains dissolved minerals that deposit on the cotton wick, reducing its water uptake and degrading measurement accuracy over time. If distilled water is unavailable, boiled and cooled clean water serves as an acceptable substitute. Zeal Wet and Dry Hygrometer

Q: Is the wet and dry bulb hygrometer suitable for greenhouse use in Bangladesh?

A: Yes, absolutely. Greenhouse managers across Bangladesh widely use the wet and dry bulb hygrometer to monitor temperature and relative humidity at plant canopy level. Its battery-free design makes it maintenance-friendly in humid, high-temperature greenhouse environments where electronic sensors frequently fail or require frequent recalibration.

Q: Does the instrument come with a calibration certificate?

A: A standard calibration certificate is available on request from ASTZ Bangladesh. This traceable certificate documents the thermometer readings against reference standards and satisfies requirements for ISO 9001, GMP-compliant pharmaceutical facilities, and food safety audits. Contact us at the time of order to include this service.

Q: What is the difference between a psychrometer and a hygrometer?

A: A psychrometer is a specific type of hygrometer that measures humidity through the wet-bulb cooling principle, using two thermometers. The term hygrometer covers all instruments that measure atmospheric humidity, including capacitive digital sensors, hair hygrometers, and psychrometers. The wet and dry bulb thermometer is therefore both a psychrometer and a hygrometer.

 

Why Buy from ASTZ

1. Authorised Supplier – ASTZ Bangladesh sources genuine, quality-certified hygrometer thermometers directly from reputable manufacturers with verifiable product documentation.
2. 1-Year Warranty Coverage – Every instrument ships with a full one-year warranty, and our local team handles all after-sales and replacement queries.
3. Expert Technical Guidance – Our team includes qualified engineers who advise on correct instrument selection, installation, and psychrometric chart usage.
4. Nationwide Fast Delivery – We deliver to Dhaka, Chattogram, Sylhet, Rajshahi, Khulna, Barishal, and all major districts within 24–72 hours.
5. Flexible Payment Options – Pay via bKash, Nagad, bank transfer, or cash on delivery — whichever method suits you best.
6. Calibration Certificate Available – We supply instruments with optional factory calibration certificates for ISO-compliant laboratories and audited facilities.
7. Replacement Parts Stocked – Cotton wicks, water reservoirs, and replacement thermometers stay in stock, minimising instrument downtime.
8. Best Price Guarantee – We match any verified lower price from an authorised supplier in Bangladesh, ensuring you get the best value every time.