I want to build project (got all the parts ordered already) that simply tells me when the sugar/water/glucose gets to the correct point and controls the temperature.
Easy enough to do, but what I can't decide on is...
Should i use a SSR or a regular Relay, since the relay is mainly going to be on until it hit's the right temprature, I think an SSR (since i'd also have to get Adequate Cooling) might not be up to the job
of a 2000watt electric frying pan without a heafty heatskink on the SSR...
The day they can invent a material / semiconductor that allows the electrons to flow like that of a piece of metal/wire the better!
Use an SSR if you can afford one rated high enough, so you need one that will take the current format least a 3000 W load. Look at how much that will dissipate, the forward volts drop from a triac is small so it might not be as much as you think.
You haven't said what your mains voltage is, could be 115V (so 17.4A for 2000W) or 230V (so 8.7A). Either way, if you use an SSR you will probably need a heatsink. The low-cost SSR option is a Fotek SSR25DA + heatsink or SSR40DA + heatsink, both of which you can source from China or HK via eBay. There is some general info on SSRs at Semiconductor relays.
Bear in mind that both mechanical relays and SSRs can fail short-circuit, so you should consider the safety implications if this system will be unattended, and maybe include a thermal cutout.
A SSR should be easier to use, since most can be controlled directly from the Arduino's 5V output. Most higher-power mechanical relays are going to require 12 or 24V for the coil (and possibly more than the 40mA supplied by the Arduino).
Grumpy_Mike:
Use an SSR if you can afford one rated high enough, so you need one that will take the current format least a 3000 W load. Look at how much that will dissipate, the forward volts drop from a triac is small so it might not be as much as you think.
Well small is a undefined term. Seems to me most SSRs drop approx 1.5 to 2 vac across their output terminals when conducting so at 2000 watt load at 120vac that could be 16.66 amps or 33.3 watts of dissipation for the package, not insignificant at all. Even if running at 220vac that is still plenty of heat that will need to be dealt with.