How to compare negative values correctly ?

Ran into problems with this very specific case. First I switched from float to int * 100. I measure small voltage changes.

Some Values of "Volt" are negative, some positive. This instruction only triggers if "Volt" is positive.

int Volt= 0;

Volt=(int)analogRead(PIN_TEST)REF_VOLTAGE/PIN_STEPS100; // Read new Value

if (Volt > -3 && Volt <= 8 ){
display.println("Switch 1");
}

So my question:
How can I make the Arduino trigger my <> statement for both, positive and negative values?

OT

Btw. The comparison of floats was even weirder. I had to use this (wrong!) <> statements to make it work correctly:

if (Volt < -0.03 && Volt >= 0.08){
display.println("Switch 1");
}

Smaller in my sense means that the value of "Volt" is f.e. -0.04. But here it only seems to take the absolute value (0.03) in account, neglecting the minus.
Also, >= 0.008 is obviously wrong, because I want to catch all the values between -0.03 and 0.08. But that is no my problem for now, since I switched all values to integer now.

I have a 1.60V offset circuit added to the probe and A1 where I also measure the offset voltage constantly. So the "real" measured value of -0.03V is 1.57V.
I skipped the part where I subtract that 1.60V.

// Measure Voltage & add offset
Volt0=Volt; // Save old Value first
Volt=(int)analogRead(PIN_TEST)REF_VOLTAGE/PIN_STEPS100; // Read new Value

counter1++;
Volt=Volt-VOffset; // add hardware offset

EDIT: Do I need signed ints here?

Hi Delta_G,

Thanks for the replies. Next time I will post the full sketch.
Meanwhile, I tracked down my problem with the calculations. I ran out of RAM. No warning nothing, just funny effects.
Once I cropped some array here and reduced some other variables it all worked. Once I increased the arrays again, it reappeared.
So for all other beginners, with funny effects better have a look at your RAM usage :wink:
Is there a way to see the RAM left? I am currently using the Arduino web editor.