I’ve been after a thermohygrograph for months – no, make that years (you know, one of those clockwork-driven paper charts with pens on levers tracing the temperature and humidity) – so that I can see what’s REALLY happening in my greenhouse. Unfortunately, new ones were unaffordable (about £500) and used ones non-existent.
Then, in rummaging the web in futile hope once again, I happened upon the Lascar EL-USB-2, and bought one right away. For about £50 (+ VAT & shipping) I got a waterproof data logger like a tubby memory stick that I just plug into my PC when I want to see what’s been going on. So, for an affordable sum I’ve got a “thermohygrograph” that is just so easy to use, takes no space, hasn’t got messy paper charts and pens, and even works out and plots the dew point for me as well!
Below is my very first trace for a day (or rather, night, as it starts and ends in the afternoon). From left to right, this is what it showed me:
I’ve learnt one important thing straight away – my dawn boost is a bit stronger than it need be, and I will be better running it at 600watts for two hours rather than 1200watts for one hour – that will also give the sun more of a chance to get up before the boost ends.
All in all, I can’t recommend this thing too highly – it was delivered instantly, was easy peasy to set up, and the instructions are in decent English with clear diagrams. It is also very well made and the program for looking at the data starts automatically and is a dream to use. Find out more at www.audon.co.uk/elusb2.html
RML, 21 Oct 2010 - May be reproduced without request.