Hand temperature probes are an option - but ideally what one wants is a way to reliably and consistently show that all of the material has reached the specified temperature for the correct amount of time.

Which is essentially impossible with a hand probe.

I'm curious to find out how well your tin or solder proves the method, Jonathan.

Thanks Elisabeth for your suggestion and I had already been in contact with Santiago who had some useful suggestions.

And Hajo - thank you also for your suggestions. We are trying to measure the temperature of sludge as it passes through a dryer. We already have some systems to measure air temperature but what we want to do is measure the sludge temperature as it passes through the dryer and ideally how it changes over time i.e. initially heating up as it enters the dryer, reaching peak temperature and then cooling gradually as heat is exhanged throughout the dryer.

At the moment we are working on getting hold of various materials that melt around the temperatures that we are interested in to try passing them through the dryer as suggested by Joe previously. At the moment it looks like it will be tin or solder.

Many thanks for your help. Jonathan.

hi..
just a quick one:

• we have used sensors and gauges of engine oil/water temperature measuring devices to measure temperature in a sun dryer for faecal sludge;
• .. and I have procured a sensor/gauge which is used by chefs in a kitchen to measure temperature in a roast in the oven... but haven't yet tried it on human excreta...

maybe this helps,
ciao
Hajo

Hi Jonathan,
I reckon Santiago Septien from UKZN in Durban, South Africa might have some suggestions as he and his PhD students have some so much work on solar sludge drying and on the LaDePa drying and pelletisation process (he's also posted on the forum in the past, search for "Santiago" in the search field). Have you already been in touch with him? If not, I can e-mail him and highlight this forum thread to him.

Other players to speak to could be the researchers with Linda Strande at EAWAG.

By the way, welcome to the Forum and I hope you'll post more often and let us know what you and Sanivation are up to! If you put "Sanivation" into the search field you can see what previous posts were made about Sanivation's work.

Regards,
Elisabeth

Thanks Joe that's interesting. I'll noodle on that idea - what things can we put in the sludge that melt at known and different temperatures.

A long time ago I remember someone trying to show that a minimum temperature had been achieved using a low-tech method.

They were exploring a material - I think it was wax but I can't remember - which you put into the sludge in small moulded pieces, and then carefully recovered them afterwards. Of course it requires something that reliably melts at a useful temperature.

I've never heard of anyone actually doing this, but I like the idea of having a way to see how much of the sludge has got to temperature.

Hi all

I am looking for a physical method to observe temperature during biomass drying and briquette production.

Ultimately I am trying to determine if a biomass dryer and/or a briquette press are able to treat fecal sludge during co-drying with wet biomass (e.g. sawdust) and when producing briquettes respectively. I had planned to review this biologically using ascaris or an alternative but have had difficulties acquiring resources.

As an alternative we're looking at physical temperature observations inside the biomass dryer or inside the briquette press. Mounting thermocouples gives an indication of the air temperature but not the biomass temperature and laser observations are not reliable enough. I'm looking at small (button sized) data loggers that we could send through the biomass dryer or the briquette press. Unfortunately they are quite expensive!

Any recommendations or suggestions would be most welcome.

Many thanks, Jonathan