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The PEM2® Enters the Market

IPI's Preservation Environment Monitor

The first Preservation Environment Monitor® (PEM®) was produced over a decade ago by IPI with funding from the National Endowment for the Humanities. The original PEM is now in use in several hundred museums and libraries in the US and abroad. This model is no longer available, but it is still fully supported by IPI.


The PEM2
The PEM2 was introduced in January 2008. This compact, highly accurate monitor is the easiest-to-use device of its kind on the market. One essential feature of the PEM2 is its method of data retrieval, which is accomplished by inserting a USB flash drive or key directly into the logger. The PEM2 detects the key and writes all its data as a plain text file (readable on a PC or Mac) within a few seconds. After uploading one or more loggers, the user takes the key to a computer, logs into the web site (, and uploads the data to the web server.

No software is required with the PEM2. Data is uploaded to, a free website created by IPI. The site accepts PEM2 data as well as Climate Notebook notebooks from the original PEM. Once registered, users can name and save the data files on their own PEMdata sites. Outdoor data from 1,400 weather stations in the US can be downloaded on the site for comparison to indoor data. The site offers graphs of temperature, relative humidity, dew point, and IPI’s six preservation metrics, which allow easy analysis of chemical, biological, and mechanical decay.

The PEM2 will run for ten (or more) years on a set of four AA batteries and will retain all ten years of data for upload at any time. The PEM2 displays temperature (in Celsius or Fahrenheit) and relative humidity.