microwave

[paulz]

we have an ancient m/wave - it works fine so no reason to change it. Usually no probs cooking food - ie if its hot its done. Some of the new quick meals are down to minutes & seconds and a few wrong either way can spoil it, I 'm sure there's a way you can calculate the wattage, it involved boiling a pint of water from cold & timing how long that took. Any ideas what the formula is?

[norfolk boy]

It works fine ? have you had it checked for radiation leakage? You can get a new one for forty pounds!

[Janetex]

I don't know about the testing, but packaged food often gives temps & times for both high & low watt microwaves. The rule of thumb for the high watt seems to be high temp for the first 1/3rd of the time then med temp for remaining time. Hope that helps

[incitatus]

Why would it suddenly start leaking radiation now? unless it had holes in it a couple of cm wide its really not too much to worry about. and in terms of radiation, its the same stuff you get from cellphones. To check the wattage: take the temperature of 1 litre of water. Put this into the mwave, then heat till it boils. time it. in seconds. multiply 4.2by (100-initial temperature) then diuvide this figure by the time taken. This gives you the kilowattage. Multioply this by 1000 to get the answer in watts.

[mac309]

There are two reconised ways of testing power outputs of microwaves, one is the IEC705 test this is to create the categorys to which you now see on packets. This test cannot be done outside a laboratory as it's based on strict rules of air & water temperatures, implements used etc.The test that us microwave engineers use is the older test which goes as follows. Take 2x 500mL pots of cold water,stir, take temp of both add together and divide by 2 (T1).Heat on full power for one minute and two seconds. Stir both and take temps and again add together and divide by 2 (T2). Take T1 form T2 to give temp rise(T) and then multipy by 70. eg (T2-T1)X70=power. This will give the power output of any old oven not having an IEC705 rating.The rusult will also be about 10-12% below the IEC705 value, or multiply by 78 will also give a similar value. The cook times on packets are guidelines only and are not gospel. food is cooked when the core is above 76'C