thermometer

25 Articles

Building A Tool To Measure Melting Point

February 8, 2013 by 5 Comments

melting-point-apparatus

When working with chemical reactions it may be necessary to test the purity of the components you’re using. This is especially true with hobby chemists as they often acquire their raw materials from the hardware store, garden center, or pool supply. [Ken] figured out how to get around the $500 price tag of a commercial unit by building this DIY melting point test apparatus.

In this image he’s using a thermocouple to monitor the temperature of the melting surface, but mentions that you can do this with an inexpensive dial thermometer and will still have great results. That melting surface is the hexagonal head of a bolt which he drilled out to provide a concave surface for the test compound. Inside the PVC pipe is the heating element from a 40W hot glue gun. He wrapped it in fiberglass fabric which is sold in the plumbing supply to protect the area around pipe joints during soldering. The rotary light dimmer feeds the electricity to the element, allowing for adjustments to the ramping speed.

Nixie Tube Thermometer

February 14, 2011 by 16 Comments

nixie_therm

After seeing a picture of a thermometer using a bargraph style nixie tube in place of a mercury column, [Juergen Grau] decided he wanted to build his own. Dubbed the “Nixietherm”, his replica looks even better than the original. He used an IN-9 Nixie tube mounted on top of a custom plastic case, all powered by a 5v USB connection. He points out that his version does not use a PIC or any other sort of processor – it is built entirely from analog circuits. There are some RGB LEDs embedded in the plastic case that make for a cool effect, but they seem to simply cycle through the colors rather than represent how warm or cold the temperature is at any given time.

[Juergen] does not give a lot of details regarding the build as far as PCB layout or a parts list is concernred, but most of that can be extrapolated from the wiring schematic he provided. He also mentions that he will be making kits available in the near future. Be sure to keep reading to see the thermometer in action.

Thanks [Brian]

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Thermos Temperature Meter

March 15, 2010 by 22 Comments

[youtube=http://www.youtube.com/watch?v=UXsxtEmKgbw]

We’re always a little surprised by how well a vacuum thermos works, but eventually the contents will cool down (or warm up depending on what’s in there). [Gamesh_] added a temperature meter to his thermos using an Arduino and a temperature sensor. The original post is in Portuguese but [Bruno] republished it in English.

The temperature sensor has been repurposed from a digital thermometer meant for taking your temperature. Holes for the LEDs making up the indicator bar were melted in the side of the plastic housing. When the hot liquid is poured out at about 0:45 into the video you can glimpse the Arduino hanging our on the other side of the pot and a power cord running off behind the laptop. It would be nice to see this migrated over to a less powerful chip and run from a small coin cell, but we like the concept.

Better Temperature Readings Using An Aspirated Thermometer

December 17, 2009 by 15 Comments

Unlike regular thermometers that can get incorrect readings because of the sun’s heat, shading, and airflow, aspirated thermometers isolate the temperature sensor from precipitation and the sun, while providing constant air circulation. Take ten 1-wire T2SS boards and combine them with DS18B20s and you’ve got yourself the start of an aspirated thermometer. A foot of PVC pipe, fans, and the above mentioned parts and you’ll have accurate temperature readings in no time.

[Dave] made his to control a natural gas boiler, pumps, and 11 gas-fired unit heaters for a combined output of 5.3 million BTUs per hour – keeping his greenhouse nice and toasty.

Update: Thanks Firetech for pointing out our silly typo.

Meat Thermometer Using Predictive Filtering

June 17, 2009 by 20 Comments

meatthermoafteradjustment

The guys over at NerdKits put together a really informative video on a meat thermometer using predictive filtering which is viewable below. The video, supplemental text, and code is available on their website. The thermometer is constructed of a LM34 temperature sensor attached to a piece of 12 gauge solid copper wire. The thermometer signal is processed on an ATmega168 microcontroller and visualized using the pygame library for python. The real gem in this project is their excellent explanation of predictive filtering, which could easily be utilized for a large number of projects.

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Thermosmart: Arduino Thermostat

March 12, 2009 by 26 Comments

smartstat

[Chris] sent in the Thermosmart. It is an Arduino controlled thermostat. It has a web interface which allows him to see the current temperature and make adjustments from remote locations. He can set heating or cooling to on, off, or auto and adjust the ranges as well. We’ve seen similar done with an Arduino before, even one with a nice LCD interface. This could possibly be useful for remote plant monitoring as well.