The x will be which object, such as which CPU or which GPU if you have more than one. If you only have one, it will be 0.
TA = Ambient temperatures
TAxP = ambient temp
TC = CPU temperatures
TCxD = CPU die temp
TCxH = CPU Heatsink temp
TCxP = CPU proximity
TN = Northbrige temperatures
TNxP = Northbridge position temp
TG = GPU temperatures
TGxH = GPU heatsink
TGxF = GPU fan
TGxP = GPU position
TB = battery temperatures
Ts0P = sensor near palm rest
This is from an older spec sheet:
Bit Hex Dec Key Description
--- ------ ----- ---- ------------
0 0x0001 1 TC0H CPU Heatsink
1 0x0002 2 TG0H GPU Heatsink
2 0x0004 4 TH0P HDD Proximity
3 0x0008 8 TO0P ODD Proximity
4 0x0010 16 Tm0P MLB Proximity
5 0x0020 32 TA0P Ambient
6 0x0040 64 Tp0P Power Supply Proximity
7 0x0080 128 TW0P Wireless (Airport) Proximity
8 0x0100 256 TC0P CPU Proximity
9 0x0200 512 TC0D CPU Die
10 0x0400 1024 TG0P GPU Proximity
11 0x0800 2048 TG0D GPU Die
12 0x1000 4096 TL0P LCD Proximity
13 0x2000 8192 SGTT GPU Heatsink Throttle Threshold