PEM2® Hardware Support

Technical support for the Preservation Environment Monitor (PEM2®). This compact, highly accurate data logger is the easiest-to-use device of its kind on the market. The outstanding feature of the PEM2 is its method of data retrieval: USB flash drive (commonly called a thumb drive or USB key) inserted directly into the logger.

When You Receive the PEM2

Upon arrival, a crescent moon icon will be displayed on the PEM2, indicating that the monitor is in "sleep" mode. Turn the monitor on by inserting any USB flash memory drive into the slot on the right side of the PEM2. The moon will disappear, and an hourglass icon will flash on and off for approximately 10 seconds. Then the monitor will alternately display temperature and relative humidity on a 15-second schedule. The monitor is now on and collecting data.

Retrieving Data from the PEM2

Any USB flash drive may be used, but IPI offers a 2 GB flash drive that is made to accompany the PEM2. Regardless of the type you select, we recommend you dedicate one flash drive to your PEM2's and consistently use this same flash drive to download the data. We have found that using a single, dedicated flash drive results in the fewest complications while retrieving the PEM2 data.

Insert any USB flash memory drive into the slot on the right side of the PEM2. The hourglass icon will flash on and off. Remove the flash drive when the hourglass disappears. A data file is now on the flash drive. Data files are named using the convention of P2_ followed by the unique serial number of the monitor (e.g., 00030). The three-character file extension reflects the upload number (e.g., 001 for the first upload). Thus, the file name will look like the following: P2_00030.001.

Using PEM2 Data

Data from the PEM2 can be imported directly into the Climate Notebook software. The file can be opened in Microsoft Excel or other database type software. The text file can be viewed using Notepad, Microsoft Word, or other document-editing software. PEM2 data can be uploaded and stored here on the eClimateNotebook website.

Display Icons

Under specific circumstances, any of the following five icons may display on the PEM2's screen:

busy icon The blinking hourglass indicates that the PEM2 is busy either uploading data to a flash drive or is executing a command. Allow the hourglass to stop blinking before removing the flash drive. If the hourglass will not stop please contact Technical Support at
battery low icon The battery icon indicates that the batteries are low.
sleep icon The flashing "half moon" icon indicates that the PEM2 is in the energy saving ship mode. The icon displays only when the PEM2 is just purchased and out of the box. Inserting a USB flash drive into the port on the right side of the PEM2 will start the normal operation mode and begin collecting data.
full icon The 100% icon indicates that the inserted flash drive is full.
FIXME icon The flashing wrench icon indicates there is a problem with the operation of the PEM2.
Please contact Technical Support at


Enclosure material: ABS plastic
Dimensions: (h x w x d): 7.3 cm (2.875") x 9.5 cm (3.75") x 3.8 cm (1.5")
Mounting: Shelf or wall mount; secure mounting possible


200g (7 oz.)


Outputs temperature and humidity alternating in a 15-second cycle

Operating Range

-40C to 65C (-40F to 150F)


Sensor type: Texas Instruments TMP123 Digital Temperature
Sensor Accuracy: 0.5C (1F) across operating range
Resolution: 0.1C (0.1F)


Sensor type: Thin film polymer capacitance sensor, Sensirion SHT75
Operating range: 0% to 100% RH, non-condensing
Accuracy: 2% RH (10% to 90%), 3.5% RH (0% to 10% and 90% to 100%) across operating temperature range


Certificate of NIST-traceable calibration provided from Thunder Scientific Model 2500 Humidity Generator



Holds more than 20 years worth of data at a fixed sample rate of 30 minutes (each 30-minute data point is an average of six readings taken at 5-minute intervals)

Data Retrieval

Via standard USB flash drive (USB 1.0, 2.0 supported; USB flash drive not supplied)
Data written as text file readable in PC or Mac


Uses AA lithium (supplied) or alkaline batteries
Battery life is typically +/- 5 years


RoHS compliance (reduction of hazardous substances)


The PEM2 is guaranteed against defects in manufacturing for a period of three years from date of purchase. Units that fail under reasonable conditions of use during that time will be repaired or replaced free of charge. A fee will apply to repairs made after the three year warranty period.


Recalibration for temperature and RH accuracy is recommended every three years. Recalibration service includes sensor recalibration or replacement, battery replacement, firmware upgrade if applicable, and issuance of a new certificate of calibration.

Choose what values appear on the PEM2's display:

Choose the Temperature Units of the PEM2 display:

Choose the numerical format for writing the data log file. The default data format setting for every PEM2 is "Celsius with decimal point" (Example: 21.0 C). It is important to change this setting to reflect the Regional and Language settings of your local machine because this format affects how some programs process numbers.

Checking the "Clear Logger Memory" box will clear all the accumulated data from the datalogger. We do not recommend clearing the logger memory unless you are moving the logger to a new location. Back-up the data on your logger to your computer before clearing the data.

Checking the "Reset Timestamp" box will reset the timestamp on your PEM2 to 30 seconds into the future. We do not recommend resetting the timestamp unless you have been explicitly told to do so. Back-up the data on your logger to your computer before resetting the timestamp.

Checking the "Set To Ship Mode" box will restore your logger to the "sleep" mode it was in when you received it.

Use this command to download all the data stored in your PEM2. This command only applies to PEM2s purchased or recalibrated after April 7, 2009 due to the new PEM2 firmware. PEM2s purchased or recalibrated prior to this date will not be affected by this command.

A National Institute Standards and Technology (NIST) traceable calibration should be performed every two or three years, or whenever you question the readings that you are getting. If the monitor is in an environment where there are long periods of very high relative humidity (RH), it should be recalibrated more often.

The PEM2 cannot be calibrated in the field by the user. Image Permanence Institute (IPI) offers recalibration including battery replacement for $150 for each PEM2.

Submit an online recalibration request.

For further information, you can contact IPI at:

Image Permanence Institute
Rochester Institute of Technology
70 Lomb Memorial Drive Rochester, NY 14623-5604

(585) 475-5199

Battery Specification

The PEM2 uses four AA lithium batteries. With the first set of supplied batteries, the PEM2 has an estimated battery life of +/- 5 years.


battery low icon If the battery icon displays on the PEM2's screen, it indicates that the batteries are low and should be changed.


Changing the Batteries in your PEM2

The batteries will be replaced by IPI each time you send your PEM2 to be recalibrated. Battery replacement is included in the cost of recalibration.

If necessary, it is possible to replace the PEM2 batteries in the field.

The PEM2 data logger takes 4 lithium (recommended) or alkaline AA batteries (lithium batteries are strongly recommended for Freezer Storage locations).

WARNING: Once you remove the batteries from the PEM2, the logger’s timestamp may potentially revert to 2007 and generate unusable data. A link to instructions for resetting the timestamp is included below.

To change the batteries:

  1. Using a long Phillips head screwdriver, remove the 4 screws that hold the case together and lift off the back of the case
  2. Disconnect the battery holder from the PC board by unplugging the two-pin socket **Please Note the orientation of the socket before removing!**
  3. Using the Phillips head screwdriver, remove the single screw and then remove the battery holder backing
  4. Remove the old batteries (taking note of the + and – positions of each cell) and replace with new ones
  5. Replace the battery holder backing and replace the screw
  6. Plug in the two-pin socket to reconnect the holder to the PC Board 
  7. Replace the 4 case screws and you're done!

**It is highly recommended that you reset the PEM2’s timestamp after changing the batteries by following the directions in this downloadable PDF**





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eClimateNotebook® is a web-product created by the Image Permanence Institute, Image Permanence Institute, an academic research center devoted to research that informs the preservation of cultural heritage collections. The Image Permanence Institute is a department of the College of Art and Design at Rochester Institute of Technology (RIT).
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