This thermochron review will cover its strengths and weaknesses and will cover the entire range from the DS1921G up to the DS1923.
The thermochron has now been on the market for over a decade. When it was first released it sold for under half the price of every other logger on the market. Now the price of other loggers have moved down to compete, but it still has a number of features that set it apart. There has also been a number of new models released.
The original DS1921G (our TC) introduced a range of features that are standard throughout the entire range. The small stainless steel housing provided probably the most robust housing available for any data logger. It could be used in harsh environments including wet or dirty conditions. It was incredibly small which allows it to be placed in almost any area or item that needs to be monitored.
The small size was actually a disadvantage for many users, and so the standard options of the plastic fobs to hold it have always been popular. These holders made it easier to see the unit, place it, and remove it from the reader.
The DS1921G (TC) offered a very good range (-30°C to 85°), average accuracy (1°C), and average resolution (0.5°C). It is great for monitoring temperature where large variations are expected, but not where you require precision.
The range was increased to have the DS1921H (TCH) and DS1921Z (TCZ) which provided a much reduced temperature range but with greater resolution. The TCZ has a range of -5° to 25°C with a resolution of 0.125°C and an accuracy of about 0.6°C. It is the low cost fridge model.
The DS1921 range all have 2,000 reading capacity. That’s more than sufficient for the majority of users.
The DS1922 range improved both the reading capacity and resolution. At low resolution (0.5°C) they would store 8,000 readings and at high resolution (0.0625°C) they would store 4,000 readings. The DS1922L (TCS) has the same range as the TC (-30°C to 85°C) but with the better memory and resolution. Hence it became known as our “super” model.
The DS1922 range includes two additional models that pushed the range upwards. The TCX was first and covered 0°C to 125°C (X for “eXtreme”) and the TCU then went further with 15°C to 140°C (U for “Ultra-extreme”). For monitoring temperatures over 70°C the TCX should be used, and for temperatures over 120° the TCU.
Finally the DS1923 (HC) is the temperature and humidity model.
The entire range is ideal for auditing.
They have two common weaknesses:
– Lack of indicator means that the user doesn’t know if there is a problem until they download the results. For many applications this isn’t a problem. Where it is, consider using a Logtag.
– Lack of external probes means that it can only monitor where it is. The higher temperature range, however, means that it is capable of logging temperatures in places where many other loggers can’t go