We recently had a customer send us a few photos of an installation. This blog tells his story of a very clever way of calibrating in high winds.
This one is at Fishguard Wastewater Treatment Works and here he’s utilised the extension bracket to raise the sensor bracket.
Also the sensor probe shafts have the old style support brackets fitted so he made some 6mm nylon spacing blocks to raise the stainless steel bracket in order that he could fit the new collars onto the shaft.
He recently commissioned some new DO & MLSS probes at another Wastewater Treatment works at Fishguard. The location of the site is at the end of the Stena Irish Ferry Terminal next to the breakwater and is very exposed to severe weather conditions even at the best of times.
He was struggling to hold the 2 metre Flex Tech shafts and DO probes in a sample pot of ABB Zero Oxygen solution to perform the zero calibration process as part of the initial setup. He had used temporary cable ties to hold the shaft yet it was still wobbling all over the place because of the flexible rubber coupling.
He thought to himself that there must be a better solution than this when he remembered the extra sensor and handrail extension brackets he had in the van for another install. He fitted the brackets and also extra collars to the shafts and was instantly able to calibrate the sensors hands free. He then installed some more extra collars to the MLSS probe shafts and was able to also perform the zero & grab sample calibrations with ease.
Since fitting the new “calibration brackets” at other sites he found that sometimes the original collars used to hold the probes in the tank can be adjusted to a “happy medium” to both hold the probe in the tank and also in the “calibration bracket” whereas on other installations an extra set of collars are required. Therefore he would suggest that it may be advantageous to offer to the customer the option to purchase an extra pair of collars separately from a sensor bracket in order to mix and match.
Possibly colour coding the brackets and collars (if at all possible) could be a future improvement, if the idea takes off, to prevent fitting the sensors at the wrong height whilst placing back in the tank. Also if the stainless steel bracket could be colour coded with a “hi vis” colour this would make it stand out from the hand railing and prevent anyone bumping into it. This was also the reason he placed his installations as close as possible to the 7300 monitor assembly.