---
product_id: 165743724
title: "SMARTRO SC42 Professional Digital Hygrometer Indoor Thermometer Room Humidity Gauge Pro Accuracy Calibration"
brand: "smartro"
price: "€ 36.43"
currency: EUR
in_stock: true
reviews_count: 8
category: "Smartro"
url: https://www.desertcart.fi/products/165743724-smartro-sc42-professional-digital-hygrometer-indoor-thermometer-room-humidity-gauge
store_origin: FI
region: Finland
---

# ±0.5℉ & ±2%RH accuracy 10-sec update rate 3.5'' HD backlit display SMARTRO SC42 Professional Digital Hygrometer Indoor Thermometer Room Humidity Gauge Pro Accuracy Calibration

**Brand:** smartro
**Price:** € 36.43
**Availability:** ✅ In Stock

## Summary

> 🌡️ Stay ahead of your indoor climate game with pro precision!

## Quick Answers

- **What is this?** SMARTRO SC42 Professional Digital Hygrometer Indoor Thermometer Room Humidity Gauge Pro Accuracy Calibration by smartro
- **How much does it cost?** € 36.43 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.fi](https://www.desertcart.fi/products/165743724-smartro-sc42-professional-digital-hygrometer-indoor-thermometer-room-humidity-gauge)

## Best For

- smartro enthusiasts

## Why This Product

- Trusted smartro brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Versatile Placement:** Magnet, wall mount, and stand options let you position it anywhere—from nursery to wine cellar.
- • **Track Comfort Trends:** 24-hour and all-time max/min records help you maintain the perfect indoor atmosphere.
- • **Effortless Visibility:** Large 3.5-inch HD backlit screen ensures clear readings even in low light.
- • **Precision You Can Trust:** Swiss sensors deliver pro-grade accuracy with ±0.5℉ temperature and ±2% humidity tolerance.
- • **Instant Climate Insights:** Updates every 10 seconds to keep you ahead of indoor environment changes.

## Overview

The SMARTRO SC42 is a professional-grade digital hygrometer and thermometer featuring Swiss sensors for ±0.5℉ and ±2%RH accuracy. It updates readings every 10 seconds on a large 3.5-inch backlit LCD, tracks 24-hour and all-time max/min temperature and humidity, and offers versatile mounting options including magnets and wall hooks. Pre-calibrated and manually adjustable, it’s ideal for maintaining optimal indoor comfort in any environment.

## Description

desertcart.com: SMARTRO SC42 Professional Digital Hygrometer Indoor Thermometer Room Humidity Gauge Pro Accuracy Calibration : Patio, Lawn & Garden

Review: Well Crafted Accurate Item - This is a solid little unit that provides helpful/accurate information. Easy to read numbers and graphs, and even has a light when neeeded! I had no idea how little indoor humidity I had in the winter time until I got this. Now I'm easily able to guage/achieve a more healthy indoor environment. A must have for cooler/cold climates. Would purchase again and am considering giving as a useful gift.
Review: Just what I needed - Have needed this forever. Works great, gives me a more accurate read in the house (which is a metal home). Shows temperature and variations. Has easy to read "humidity" section. Did not realize it had a magnet until I put it close and it basically jumped out of my hand to the wall...so I can guess it is a good one...Worth the money. Have not used the bluetooth and probaly will not.

## Features

- The Best Industrial Grade Accuracy: Humidity gauge with built-in Swiss sensors, it detects subtle humidity and temperature changes and updates readings in each 10 seconds. Temperature tolerance is within 0.5℉(-4 to 158℉) and humidity is 2%RH (1 to 99% RH). The digital hygrometer is pre-calibrated for accurate temperature and humidity measurement.
- Easy-to-Read Backlit Display: Temperature and humidity monitor with 3.5'' large HD LCD screen. A simple touch on the top will turn on backlit for 10 seconds. Clear and power-saving, reading more easily under weak backlit. Reliable operating buttons on the back for manual setting or °F/°C switching. Note: The backlit in the pictures is all in ON state. The backlit is not always on.
- 24 Hours All-time Max Min Records: The room thermometer displays high and low records for the past 24 hours and All-time; Indoor thermometer measure conditions and identify changes in temperature and humidity instantly. Comfort Indicator ensures proper humidity control, helping you to maintain a comfortable atmosphere in your home.
- Wide Applications with More Mounting Options: With a retractable stand, two powerful magnets and a wall-mount hole, this digital thermometer indoor can be easily attached to your refrigerator, wall or placed on a table. Suitable for baby’s room, nursery, office, closet, incubator, greenhouse, garden, wine cellar, basement critter terrarium etc. Note: This thermometer cannot connect to phones.
- Calibration Supported: The monitor can be manually calibrated to improve data readings when product placement or environmental factors impact your data accuracy. Powered by 2x1.5v AAA batteries (not included).

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B07YY1FB9D |
| Battery Description | 2x 1.5v AAA batteries |
| Best Sellers Rank | #1,204 in Patio, Lawn & Garden ( See Top 100 in Patio, Lawn & Garden ) #5 in Weather Hygrometers |
| Brand | SMARTRO |
| Brand Name | SMARTRO |
| Color | black |
| Customer Reviews | 4.6 out of 5 stars 6,877 Reviews |
| Included Components | 1 thermometer 1 manual |
| Item Dimensions W x H | 3.4"W x 3.4"H |
| Item Weight | 0.13 Kilograms |
| Manufacturer | SMARTRO |
| Mounting Type | Wall Mount |
| Product Dimensions | 3.4"W x 3.4"H |
| Temperature Accuracy | +/-0.5 Degrees Fahrenheit |
| Unit Count | 4.64 Ounce |
| Upper Temperature Range | 158 Degrees Fahrenheit |
| Voltage | 3.0 |
| Warranty Description | 13-month warranty except for artificial damages |

## Product Details

- **Color:** black
- **Brand:** SMARTRO
- **Product Dimensions:** 3.4"W x 3.4"H
- **Item Weight:** 0.13 Kilograms
- **Battery Description:** 2x 1.5v AAA batteries

## Images

![SMARTRO SC42 Professional Digital Hygrometer Indoor Thermometer Room Humidity Gauge Pro Accuracy Calibration - Image 1](https://m.media-amazon.com/images/I/71J0pGYeMFS.jpg)

## Available Options

This product comes in different **Number Of Items** options.

## Questions & Answers

**Q: Does this display Humidity or does it display Relative Humidity?**
A: From the Amazon product page, Specifications: "Humidity Range: 1~99%RH(relative humidity)".  The Amazon page mentions "RH" at least 9 times, strongly suggesting that is what it displays.  Additionally, humidity is the amount of water vapor in a unit volume of air (independent of temperature) which is expressed in kilograms per cubic meter.  Relative Humidity is the PERCENTAGE of the maximum amount of water vapor in the air, possible at that temperature.  Because the Hygrometer reports a percentage, not a mass per volume, there can be no confusion.  RH is what you want for controlling comfort and environmental conditions (mold growth, etc,).

**Q: Can this be calibrated if needed?**
A: You can only calibrate if you have a standard that is accurate.  You can adjust the reading up and down.  I have 7 of these so I put them all in the same room for about 6 hours and I adjusted mine so it matched the rest.  The rest were within 2 of each other, this one was 4 so I made it like the others.

**Q: can you make the light stay on?**
A: Not as far as I can see. Just a very light tap on the top of the frame will light it up for about ten seconds. That seems more than enough IMHO. If left on too much, the battery would drain sooner. Just a very very light tap.

**Q: Your product information states: "calibration certification from aerospace institute for metrology and measurement technology" missing cert. doc?**
A: I have never looked for any certification's. I did a comparison test with 4 different instruments and liked this model best, so I purchased 4 or 5 of them. They have been working fine in my home and hobby woodworking shop.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Well Crafted Accurate Item
*by P***S on January 18, 2026*

This is a solid little unit that provides helpful/accurate information. Easy to read numbers and graphs, and even has a light when neeeded! I had no idea how little indoor humidity I had in the winter time until I got this. Now I'm easily able to guage/achieve a more healthy indoor environment. A must have for cooler/cold climates. Would purchase again and am considering giving as a useful gift.

### ⭐⭐⭐⭐⭐ Just what I needed
*by C***N on January 15, 2026*

Have needed this forever. Works great, gives me a more accurate read in the house (which is a metal home). Shows temperature and variations. Has easy to read "humidity" section. Did not realize it had a magnet until I put it close and it basically jumped out of my hand to the wall...so I can guess it is a good one...Worth the money. Have not used the bluetooth and probaly will not.

### ⭐⭐⭐⭐ Accurate as far as I've been able to test it.
*by B***Y on December 11, 2025*

Would give this 5 stars but I haven't had it that long. Nicely designed unit, easy to read and doesn't take up too much space.

## Frequently Bought Together

- SMARTRO SC42 Professional Digital Hygrometer Indoor Thermometer Room Humidity Gauge Pro Accuracy Calibration
- ThermoPro TP55 Digital Indoor Hygrometer Thermometer, 4-Inch Temperature / Humidity Monitor with Touchscreen and Backlit, Indoor Room Thermometer / Humidity Meter for House Home Greenhouse
- ThermoPro TP50 Digital Hygrometer Indoor Thermometer Room Thermometer and Humidity Gauge with Temperature Monitor

---

## Why Shop on Desertcart?

- 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016
- 🌍 **Shop Globally** — Access 737+ million products across 21 categories
- 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price
- 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members)
- 🔒 **Secure Payments** — Trusted payment options with buyer protection
- ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews

**Shop now:** [https://www.desertcart.fi/products/165743724-smartro-sc42-professional-digital-hygrometer-indoor-thermometer-room-humidity-gauge](https://www.desertcart.fi/products/165743724-smartro-sc42-professional-digital-hygrometer-indoor-thermometer-room-humidity-gauge)

---

*Product available on Desertcart Finland*
*Store origin: FI*
*Last updated: 2026-02-14*