---
product_id: 396801196
title: "SC42 Professional Digital Hygrometer Indoor Thermometer Room Humidity Gauge Pro Accuracy Calibration"
brand: "smartro"
price: "$88"
currency: NZD
in_stock: true
reviews_count: 6
category: "Smartro"
url: https://www.desertcart.nz/products/396801196-sc42-professional-digital-hygrometer-indoor-thermometer-room-humidity-gauge-pro
store_origin: NZ
region: New Zealand
---

# ±0.5℉ & ±2%RH accuracy Low power 2x AAA 10-sec update rate SC42 Professional Digital Hygrometer Indoor Thermometer Room Humidity Gauge Pro Accuracy Calibration

**Brand:** smartro
**Price:** $88
**Availability:** ✅ In Stock

## Summary

> 🌡️ Stay ahead of humidity swings with pro-grade precision!

## Quick Answers

- **What is this?** SC42 Professional Digital Hygrometer Indoor Thermometer Room Humidity Gauge Pro Accuracy Calibration by smartro
- **How much does it cost?** $88 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.nz](https://www.desertcart.nz/products/396801196-sc42-professional-digital-hygrometer-indoor-thermometer-room-humidity-gauge-pro)

## 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

- • **Backlit HD Display:** Large 3.5'' screen with touch-activated backlight for effortless reading anytime, even in low light.
- • **Precision Swiss Sensors:** Industrial-grade accuracy with ±0.5℉ temperature and ±2% humidity tolerance keeps your environment perfectly balanced.
- • **24-Hour Max/Min Tracking:** Automatically records daily highs and lows so you can optimize comfort and protect valuables.
- • **Instant 10-Second Updates:** Real-time monitoring with rapid refresh rate ensures you never miss subtle changes in your space.
- • **Versatile Mounting Options:** Magnetic, wall-mount, or stand placement adapts seamlessly to your home, office, or specialty spaces.

## Overview

The SMARTRO SC42 is a professional digital hygrometer and thermometer featuring Swiss sensors for industrial-grade accuracy. It updates readings every 10 seconds with ±0.5℉ temperature and ±2% RH humidity tolerance. The device boasts a large backlit LCD, 24-hour max/min records, manual calibration, and versatile mounting options, making it ideal for maintaining optimal indoor climate in homes, offices, and specialized environments.

## Description

SC42 Humidity and temperature monitor is the perfect household device to keep you and your family's living conditions optimal. Built in with high precision sensor, it gives you reliable and highly accurate reading.

Review: Reliable product - Reliable product
Review: I use it for keeping my acoustic guitars at the right humidity levels (40~50%) which need an ajustable calibration offset controls (use humidity pack for control reference). Works fine and nice to have a readout backlighting when needed… (Cheaper hygrometers have no controls and can often be inaccurate up to 10%…)

## 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 |
| Item model number | SC42 |
| Manufacturer | SMARTRO |
| Product Dimensions | 8.64 x 3 x 8.64 cm; 130 g |

## Product Details

- **Battery description:** 2x1.5v AAA batteries
- **Brand:** SMARTRO
- **Colour:** black
- **Item weight:** 0.13 Kilograms
- **Product dimensions:** 8.6W x 8.6H centimeters

## Images

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

## 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

### ⭐⭐⭐⭐⭐ Reliable product
*by S***T on 17 September 2024*

Reliable product

### ⭐⭐⭐⭐⭐ Review
*by S***E on 5 January 2026*

I use it for keeping my acoustic guitars at the right humidity levels (40~50%) which need an ajustable calibration offset controls (use humidity pack for control reference). Works fine and nice to have a readout backlighting when needed… (Cheaper hygrometers have no controls and can often be inaccurate up to 10%…)

### ⭐⭐⭐⭐⭐ Review
*by T***M on 12 November 2022*

I brought one checked it via a salt test bang on 75% brought another same as bang on 75%. Very pleased with the accuracy, very easy to use & has a decent magnet to hang up. to verify if your meter is correct put it in a plastic container with a cap filled with salt add a very small amount of water to the salt so you can still pick it up & it doesn’t run, seal it properly leave it a full 24hrs and it should read 75% if not it’s out & needs calibration )

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*Product available on Desertcart New Zealand*
*Store origin: NZ*
*Last updated: 2026-02-17*