We've detected you are coming from a location inside the Americas.

Please choose one of the following:

Global sites: BSRIA Inc BSRIA SARL BSRIA Business Consulting (Beijing) Co., Ltd.
Phone+44 (0) 1344 459314 Contact Instrument Solutions

Grant Instruments Yoyo 2YL-RH20-4M, 2YL-RH20E-4M, 2YL-RH23-4M and 2YL-RH23E-4M

Hover to zoom

The compact simple to use 2YL-RH20-4M, 2YL-RH20E-4M, 2YL-RH23-4M and 2YL-RH23E-4M Yoyo data loggers from Grant Instruments are designed to measure temperature and humidity with a 4 million readings standard memory. The sensors are covered by a rugged IP65 housing to protect them from the elements.

The 2YL-RH20E-4M and 2YL-RH23E-4M models are fitted with 100 mm probe for external fitting.

The 2YL-RH23-4M and 2YL-RH23E-4 models has three integral sensors. In addition to measuring temperature and humidity, this instrument also has the capability of measuring barometric pressure.

Product Features

  • 4 model types
  • Range of accessories
  • Calibration options
  • Document downloads

Instrument product options

1. Select a model (4 available)

Continue to select accessories

2. Select accessories

3. Select a calibration



Standard delivery includes: 1 data logger, 1 standard battery, software YoyoView, USB cable, manual, and manufacturers declaration of conformity

Grant Instruments offers a range of Yoyo data loggers including versions for temperature, humidity, condensation, extra-low voltage, strain gauge, voltage, current, pulse, barometric pressure, as well as light and solar radiation. Please contact our sales team on 01344 459314 or sales@bis.fm if the version you require is not listed within the website.

Basic YoyoView software

The basic software, included with the logger is suitable for configuring the data logger, downloading and exporting basic data. All loggers are connected to a PC or laptop via a USB cable.

YoyoView Plus software

In addition to the functionalities of the basic software, the optional upgrade offers more complex analyses of data, charts and statistics.

  • Three scaleable Y-axes
  • Zoom function
  • Cursor readings
  • Display in spreadsheet format
  • Combination of a series of measurements in one chart
  • On-line metering
  • Statistical functions


Type 2YL-RH20-4M and 2YL-RH20E-4M integral temperature and humidity sensors

Ambient temperature range     -40 to 90 °C

Measuring range     -40 to + 90 °C

Accuracy      ± 2 % RH and ± 0.3 °C

Internal sensor resolution      0.01 K

Memory capacity (readings)      4 million

Dimensions d x h      RH20 - 50 mm x 30 mm      RH20E - 50 mm x 130 mm

Sensor type     RH20 - 1 x temperature, 1 x humidity      RH20E - 1 x 100 mm ext. temperature, 1 x humidity steel tube

Humidity sensor (internal and external)      0 to 100 % rh / 0.01 % rh

Logging interval      1 second to 24 hr

IP rating     IP65

Battery type      Lithum (LITH-12)

Battery life      4 years @ 1 min. / 230 days @ 10 sec. / 25 days @ 1 sec

Type 2YL-RH23-4M and 2YL-RH23E-4M Specification similar as 2YL-RH20(E) models except with the following additional features:

Accuracy      ± 1.5 % hPA / ± 0.5 % hPA

Dimensions d x h      RH23 - 50 mm x 33 mm      RH23E - 50 mm x 130 mm

Sensor type     RH23 - built-in temperature, rh and pressure      RH23E - built-in temperature and rh, 2 x ext. PT1000

Barometric pressure range & resolution 10 to 1100 hPa / 0.1 hPa

Logging interval      1 second to 24 hr or Fastmode 2 Hz



Grant Yoyo logger data sheet

  • Technical Document
  • PDF file
  • 1 MB

Grant Yoyo logger user manual

  • Technical Document
  • PDF file
  • 1 MB

Grant YoyoGraph software user manual

  • Technical Document
  • PDF file
  • 1 MB
Visa, Visa Debit, Mastercard, Maestro cards accepted BSI ISO 9001 Cyber Essentials Investors in People