ML4000 RHT Series of RH/T Data Loggers

ML4000 RHT Series of RH/T Data Loggers

The Hanwell Pro ML4000 RHT Series of data loggers provide an accurate humidity measurement and discreet design typically for heritage applications.

Click on the individual products below for more information.

ML4000 Humidity Data Loggers

The ML4000 RHT series of data logger units are well established as the most flexible humidity sensors on the market today. Each unit has been designed to be compatible with a wide range of temperature and humidity probes to provide accurate and reliable measurement specifically selected for conservation requirements.

Additionally, depending on the format required by the user, temperature and humidity data can be downloaded directly to a local PC using a USB cable for automatic notification and detailed analysis.

The units are powered by a single 3.6 Volt AA Lithium battery, which can be replaced by the user as and when required. The battery life will be dependent on the method of data collection, but can last up to 3 years, with notification of when a change is required.

Product Features

  • LCD display with data readings and battery life
  • Logger memory capacity 100,000 readings
  • Easily accessible battery and USB socket
  • Supports (optional) hidden wall brackets
  • Complies with RoHS, EU directives and WEEE
  • Carries CE Marking
  • Up to 3 years battery life (depending on format of data retrieval)
  • Superior performance hardware with high accuracy sensors


  • Assists with museum accreditation
  • High performance technology with accurate probes
  • Designed for discreet monitoring
  • Ensure comfortable environment for visitors
  • Prevent damage to organic materials

Related articles:

  • Combine ML4000 units with our humidifiers and dehumidifiers for complete humidity control – read more 
  • What is relative humidity? – Click here

Contact us to talk about your specific application or to discuss how our ML4000 range can assist with multiple measurement options.

Manufactured by Hanwell | Ellab