Probes attach to 
  the 1521 and 1522 using Harts own INFO-CON connector. The 
  INFO-CON 
  (partially based on U.S. Patent 5,857,777) allows you to change the probes you 
  use without requiring 
  you to reprogram your readout. A memory chip in the INFO-CON stores all the 
  critical information 
  about your probe, including its serial number, recall date, and calibration 
  constants.  
      When you connect 
  your probe, the 1521 automatically recognizes whether youre using an RTD 
  
  or thermistor and downloads the calibration constants and type of conversion 
  specific to your probe.
  It also checks the recall date stored in the INFO-CON to verify it has not expired. 
  To dedicate a single 
  probe to your readout, disable the password-protected interchangeability function 
  and your thermometer 
  will read only the probe you specify.  
      Forget entering 
  calibration constants yourself, and dont worry about the mistakes that 
  can so easily occur 
  during that process. You dont even need to select your sensor type. Its 
  all stored in the INFO-CON. 
  Just plug in your probe and youre ready to take readings.  It doesnt 
  get any easier.  
      Information is 
  loaded into the memory of the INFO-CON by Hart when you purchase a probe or 
  have a
  probe recalibrated by Hart. Alternatively, you may load your own information 
  into an INFO-CON through the
  Handheld Thermometer or through Model 9934 LogWare.  
      If youd like 
  to use a Hart Handheld Thermometer with probes you already own, no problem! 
   
  Spare connectors are available.  They easily connect to your probes, and 
  you can program them yourself.  
 Model 1521 LLK  
  
      The 1521 Little 
  Lord Kelvin uses a menu system for convenient access to all functions. Calibration 
  and sensor
  programming functions are password protected 
  to help prevent unauthorized access.  
      Min 
  and Max functions store the lowest and highest readings since the 
  last reset. The Hold 
  function freezes and stores the current reading (up to six may be stored) for 
  later recall. And the Delta 
  function computes the difference between the current reading and a reference 
  value, which may 
  be recorded at any time.  
      Each thermometer 
  comes complete with rechargeable nickel-metal-hydride batteries, an AC 
  adapter/charger, an RS-232 cable for connecting to your PC, and a spare INFO-CON 
  connector.  
  Every unit also includes a NIST-traceable calibration with actual resistance 
  measurements for your
  individual meter at ten point s- four representing typical RTD values and six 
  representing typical thermistor values.  
 Model 1522 LLL  
  
      The Model 1522 
  Little Lord Logger has all the power and great features of the 1521 plus the 
  ability to log data.  
  Two data acquisition modes are included.  
      In Auto Logging 
  mode, the 1522 can store up to 10,000 measurements at user-selected
  intervals, including the value, unit of measure, date, and time of each measurement. 
   If you need 
  more than one data set, stop recording any time and record as many sets as you 
  like up to a total 
  of 10,000 values. Once the 10,000 value limit is reached, recording stops, so 
  data is never lost unless 
  you tell the 1522 to clear its log.  
      The 1522 also holds 
  as many as 25 data labels in its memory so that each set of data can 
  be uniquely tagged.  Simply select one of the 25 labels youve created 
  before recording data.  
  This label is then recorded with each measurement.  
      In Demand 
  Logging mode, up to 100 individual measurements can be recorded, each 
  one tagged with
  one of the 25 data labels.  Whether you need a lot of measurements from 
  one source or single 
  measurements from many sources, the 1522 is a powerful data recording tool.  
  
      With Harts 
  9934 LogWare software, data management is easy.  Data sets gathered remotely 
  
  through the 1522 can be easily downloaded to a PC either as a single file or 
  as individual files for each 
  data set.  Link the LLL to your PC through a serial cable or its IrDA port 
  to send data as ASCII or binary files. 
  View the data, graph it, or apply alarms. With LogWare you can record data in 
  real time either from a 
  1522 or 1521 Thermometer.