Tomatoville® Gardening Forums - Review: Temperature/Humidity Data Logger for Home Use

I have been meaning to report on a new toy I got last season. The following post is a report/testimonial on a particular product. I have zero affiliation with the company aside from being a happy user:

Background:

Last year I got some money from my mother in law for my birthday and instead of frittering it away on coffee and gum I decided to I was going to buy myself a present. I thought a temperature and humidity logger would be good toy/tool to have for the garden. I work for an environmental consulting firm and we occasionally use temperature loggers for work to measure water temperatures over time. When we are done with a project, the little loggers (which are waterproof, rugged, and small) have many uses like monitoring the temp of the office fridge, how well the HVAC cooling system is working (or not), etc.

The brand and model we use at work are good because they are small and rugged. But they are relatively expensive, they don't have any screen or way to read them without downloading the data, you can't replace the batteries when they die, and you need special equipment to download and launch them. Many suppliers have models that offer more functionality, but a lot are very pricey or overly complex.

Product:

I settled on a TW-USB-1-LCD sold by ThermoWorks. This model has a good balance of cost, durability, functionality, and ease of use. It is a sturdy consumer/light industrial grade product.

Cost:

About $100 inclusive of shipping, software, etc.

Pros:

- Price
- Weather resistant (but not water proof)
- Simple to operate.
- Push a button to scroll through current and max/min readings for the duration.
- Has programmable max/min visual alarms for humidity and temperature
- Does not need any cords or special equipment to download or launch, you just plug it into the USB port on your computer like a thumb drive.
- Great battery life (a year on a single AA battery so far).
- Simple, yet functional software. Very easy to download and launch.
- Allows user to program the frequency of recording, program for remote starts once in the field.
- Storage (set to record every 5 minutes, it will record for almost two months).

Cons:
- A cap over the USB end with an "O" ring is the main weather proofing. The cap is easy to misplace and I am sure the "O" ring will need to be replaced.
- It does not allow "live" monitoring. You have to stop it and download it, although you can see the current readings and max/min on the small LCD screen at the push of a button.
- It does not have a remote hard reset, you need to do it using the software.

Use/Review

I've had it for about a year and it has been very useful, particularly for me living in Seattle. Temperatures are variable, especially in the spring and nighttime temps can easily drop into the 40's even into July. After an issue with gray mold in my unheated greenhouse last June I used the temp and relative humidity data to adjust my watering. I also used it to monitor the efficiency of a solar fan I installed and helped me balance methods of passive heat control. Outside, I have used to monitor temps before outplanting (my raised beds commonly stay about 5 degrees above the reported nighttime lows), and I used to help adjust the timing for automatic dippers throughout the summer by placing it under plants on the ground for a couple days in a row to see what the micro climate around the base of the plants was doing in terms of temps and relative humility.

Summary

While this is more of a "luxury" item for the home gardener, it is a useful tool that is not much more expensive than a decent remote-sensor digital thermometer while providing substantively more function. It has the ability to monitor and log both temperature, dew point, and relative humidity that allows the adjustment of watering and outplanting schedules, particularly in northern climates. It is easy to use and has proven very dependable so far.