During a recent UKAS audit of an accredited calibration laboratory the assessor witnessed the calibration of an SPRT using a Triple Point of Water cell (0.01 °C). For interest they decided to put the SPRT in an ICERO+ (0 °C) to see what the difference was. The ICERO+ uses water with lump ice rather than crushed cubes and is stirred using air bubbling through the mixture. The effective difference between the Triple Point value and the Icero+ value was 2 mK (0.002 °C). Not bad for an ice bath you can use with or without mains power and can be held in one hand. See the products tab to get more information or contact Dave Ayres: firstname.lastname@example.org
Answers next week but also consider how a temperature indicator would respond. The indicated temperature will increase because the PRT's resistance has increased.
Answers next week but also consider how a temperature indicator would respond.
Some of the intriguing discussions from our temperature course for more information contact Dave Ayres at: email@example.com
Our view to the questions from last week:
Just 5 questions to see if you need a temperature course. Our responses next week.
Benrhos, Rotronic Instruments and Chamois Metrology are sponsoring this year’s British University Kayak Expedition to Russia:
The images below are of our latest machined copper block for a customer’s stirred water calibration bath. It is 250 mm long by 80 mm in diameter. The probe holes are 10 mm in diameter and drilled to an impressive depth of 200 mm. Drain holes 3 mm in diameter are through drilled into the probe holes to make life easier when the block is removed from the bath and needs draining. See below for an image of the top of the block and one of the base.
Digital sensors are small millimetre sized chips that can measure anything from temperature to the carbon dioxide content in air, sometimes as a single sensor or combined such as temperature, humidity and pressure on a single miniature circuit board. Digital sensors measure the quantity then digitise the value on the chip and transmit the information via a cable or by Wi-Fi. However the signal format varies between sensor manufacturers, and although communication standards exist it can be tricky turning the sensor’s output into usable data especially if there is a mix of signals from a differing array of sensors. Benrhos can help customers with this if required.
Benrhos has produced various types of data loggers with numerous sensor inputs that have remote in/out access via Wi-Fi to them. Loggers such as for chamber temperature mapping, condition monitoring of fridges, freezers as well as incubators, and loggers for chilled transport vehicles and fire training facilities. We have also produced thermocouple based digital sensors with Wi-Fi for displaying the measurements on the Rotronic RMS system https://www.rotronic.com/en-gb/rms .
It is now possible to make accurate measurements digitally using just about any type of thermocouple or platinum resistance thermometer where ever they are located and WiFi the results to a remote location or display them locally.
How and where to measure the temperature?
Globe gas and radiation combined temperature thermometer.
Using the combined temperature measurement from inside the ball and the gas temperature measurement from the exposed thermometer, a better idea of the temperatures personnel are experiencing can be made.
The Benrhos Globe thermometer is designed to measure the combination of the temperature of gases and the effect of thermal radiation experienced by fire fighters during training and workers in a hot processing environment. From our experience the thermometers used in live fire training facilities do not measure the true temperature on those near the fire. This is mainly due to 4 reasons:
The Combi thermometer is a development based on having a black ball that is about the size of parts of a human that are likely to get too hot, such as a hand or the back of the neck. The ball is coated in a high emissivity coating so it absorbs most of the radiant heat that impinges on it. Inside the ball is a fast response thermometer that measures the combined effect of the radiation and the local gas temperature to give a truer indication of what personnel would be experiencing. Attached close to the ball is another fast response thermometer that measures the gas temperature. Its job is to pick up any rapidly changing temperature such as a steam surge. The temperatures can be displayed locally or transmitted via WiFi to remote locations.