Before you install your heater cartridge, you should double check that you both purchased and received the correct voltage cartridge. Cartridges are laser etched with their voltage, but all it is worth double-checking anyway. This process is less annoying than putting out a house fire. If value is not within expected resistance is most likely a faulty heater cartridge, if that is case, please disposal of the heater cartridge or you may have purchased or have supplied incorrect voltage.
Calculation via ohms law for the expected resistance of heater:
V x I=P
I x R=V
If you have a 12v30w heater cartridge, your multimeter should read around 4.8Ω
If you have a 24v30w heater cartridge, your multimeter should read around 19.2Ω
If you have a 24v40w heater cartridge, your multimeter should read around 14.4Ω
If you have a 24v50w heater cartridge, your multimeter should read around 11.5Ω
If you have a 24v60w heater cartridge, your multimeter should read around 9.6Ω