SL54TH / SL54TH-A Miniature Temperature & Humidity Data Logger

  • £149.00Ex.VAT
  • £212.00Ex.VAT
  • £389.00Ex.VAT
  • £513.00Ex.VAT
  • £836.00Ex.VAT
  • £1,146.00Ex.VAT
  • £1,685.00Ex.VAT

Miniature Temperature And Relative Humidity Data Logger

The SL54TH is our lowest cost miniature temperature and relative humidity data logger. It is self contained and self powered with the ability to record up to 8,000 data points. The SL54TH can operate in a temperature range of -20°C to +85°C and up to 100% RH with an accuracy of ±0.5°C and ±5% relative humidity. The SL54TH-A has an improved relative humidity accuracy of ±2% and is supplied with a UKAS 17025 traceable calibration certificate.

The SL54TH and SL54TH-A are miniature temperature and relative humidity (RH) data loggers (about the same size as a watch battery) which enables them to be inserted into small items and packages. We provide a full range of temperature and humidity data logger accessories including waterproof enclosures which can be found here.

SL54TH Temperature Humidity Data Logger 

The SL50 Button Reader interfaces to the USB port of a PC and is compatible with the user friendly, TempIT-LITE operating software which enables the logger to be set up and the data read and displayed in graphical format. Data can be stored and retrieved at a later time. The software can be up-graded to TempIT-PRO which provides various additional features such as data table view, export data to spreadsheet, email graphs and automated MKT Calculations etc. The TempIT software also automatically calculates dew point from the measured temperature and relative humidity readings. 

Starter kits are available with either two or five miniature data loggers, the USB interface lead and the TEMPIT-PRO software:

SL54TH Starter Kit

The SL54TH and SL54TH-A can calculate dew point and absolute humidity.

The USB Interface lead and software are not included as standard with this temperature & humidity (RH) data logger but you can find a full list of button data logger accessories here.


Power Internal Battery
Battery Life Typically two years at +30°C with a 10 minute sample rate
Measuring Range

-20°C to +85°C (-4°F to +185°F)
0 to 100%RH (0 to 90% continuous, 90% to 100% for short periods)

SL54TH Operating Range 


±0.5°C from -10°C to +70°C
±5%RH for the SL54TH

±0.1°C ±0.1% of calibrated span
Default temperature calibration points 0°C, +25°C & +50°C

±2%RH from 10%RH to 90%, ±5% outside of this range.
Default relative humidity calibration points 20%, 43% and 75%

Other calibration points available on request


0.5°C in low resolution mode
0.07°C in high resolution mode

Sample Rate 2 seconds to 24 hours

2 seconds to 1 minute in 5 second steps
1 minute to 1 hour in 1 minute steps
1 hour to 24 hours in 1 hour steps
Number of Readings Stored The total memory is 8,192 readings.
If low resolution mode is selected 4,096 temperature readings and 4,096 humidity readings. If high resolution mode selected, 2,048 temperature and 2, 048 humidity readings. 
Reusable When Memory Full Yes
Response Time Response times in moving air:

63% time constant
Temperature: 1 Min 29 Seconds
Relative Humidity: 3 Min 44 Seconds

10-90 % time constant
Temperature: 2 Min 50 Seconds
Relative Humidity: 9 Min 54 Seconds
Waterproofing Due to the vent required to allow humidity measurement, this device is not considered waterproof and care should be taken to avoid moisture ingress. See environmental considerations below.
Delayed Start Yes, you can specify a time and date to start logging up to 1 year in advance with one minute resolution
Software Alarms Yes, high and low alarms can be specified in the software
Intrinsic Safety Meets UL#913 (4th Edit.); Intrinsically Safe Apparatus, approval under Entity Concept for use in Class I, Division 1, Group A, B, C, and D Locations
Material 305 Stainless Steel
Dimensions 17mm diameter x 6mm high
Warranty 1 Year
Environmental Considerations Like all relative humidity sensors, when exposed to contaminants and/or conditions toward the limits of the safe operating range, accuracy degradation can result. For maximum long-term stability, the sensor should not be exposed or subjected to organic solvents, corrosive agents (e.g., strong acids, SO2, H2SO4, CI2, HCL,H2S) and strong bases (i.e., compounds with a pH greater than 7). Dust settling on the filter surface does not affect the sensor performance except to possibly decrease the speed of response.

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