Laboratory tech tip – Budget bath

By Mike Beavin

Anything used in an asphalt binder lab costing under $200 might as well be free, or that’s at least the running joke in lab tech circles.

Usually ‘laboratory grade’ ensures we get the quality and precision needed to produce quality data. Other times ‘laboratory grade’ just ensures we pay exponentially more for a product we could’ve found at Walmart. Generally, if it’s sciency it’s pricey!

We won’t find a Dynamic Shear Rheometer or Bending Beam Rheometer for sale beside the rotisserie chickens at Costco so, yea, prepare to pay up for one of those.  But what about a precision constant temperature bath? Easily $2,000 for one purchased from a laboratory supply house….  Does $150 sound better?

Travis Davis with Construction Testing Services, LLC tipped us off on one of the best lab hacks in the history of lab hacks during a recent course.

Faced with a lack of adequate bath space in their lab, Travis relied on culinary technology and innate MacGyver skills to solve the problem. Sous vide (sue vee)! French for ‘under vacuum’, a method of cooking food, especially meat or fish, by vacuum-sealing and immersing in warm water. It produces delicious, juicy results and, if used to control a constant temperature bath in your lab, it can produce delicious, juicy space in your budget!

We purchased one complete with the bath for $150 and set it at 25oC and then 50oC. We verified the temperatures with our laboratory reference thermometer at different locations in the bath and are happy to report astonishing precision. The reference thermometer reported 24.932oC and 49.997oC respectively.

Additionally, Travis reports they have installed the controller in a much larger bath than the one supplied with the product and are seeing similar precision. At approx. 7.5% the typical cost of a more sciency bath, the choice is clear: Sous vide, baby!!    

Beavin teaches the National Binder Technician Certification courses at the Asphalt Institute.