How to determine thermal inertia of a resistor? In a recent experiment I've done, I heated up some gas at constant volume using a resistor inside a glass bottle. I turned on the resistor for $\Delta t$ s, but I saw that the pressure rises for $\tau > \Delta t$ s. I attributed this extra heating to the thermal inertia of the resistor.
I've also seen that $t^*:=\tau - \Delta t$ can be neglected for the calculations as $t^* << \Delta t$, but I don't know how to justify this with equations.
The setup consists of a glass container (5.4L) with a resistor inside at 4.69V with a current of 0.432A. The resistor is located on the bottom of the glass bottle and the pressure sensor on top. Once the switch is turned on, the graph of $P$ over $t$ looks like a quadratic growing function until the maximum followed by an exponential decay.

The goal of the experiment is to determine $c_v$ of the air. To do this I have an expression $\Delta P = \frac{1}{c_v}\alpha \Delta t$ $\alpha$ being some constant. This expression is based on an assumption of the process being adiabatic but the right hand of the image being an exponential decay suggests there is a loss of internal energy through heat. This is why, assuming the loss of energy from point one to point three is the same as that from three to five, I just need determine $\Delta Q_{3-5}$ and add that to $\Delta P = P_{max} - P_{base}$. The problem with this is that I only have the time $\Delta t$, so to determine the loss of energy I can only take $\Delta Q_{3-4}$ so I somehow need to justify that $t^*$ is small compared to $\Delta t$ to approximate $\Delta Q_{3-5} \approx \Delta Q_{3-4}$
Can someone tell me whether I'm right in attributing the extra time to thermal inertia and to help me find an expression to justify $t^* << \Delta t$.
 A: I don't know the distance between the resistor and your pressure sensor. The pressure rise after the resistor is turned off may be due to the heat exchange between the resistor and the gas, but it can also be due to the finite time required for the gas to achieve thermal equilibrium.
I don't quite understand why you need to justify $t^*<<\Delta t$. You know $\Delta t$, so you know how much heat was generated, this should be enough to calculate the final pressure (assuming the losses are minimal).
EDIT (Oct 31, 2022): Thank you for adding the details of the experiment. So your sensor is relatively far from the resistor. I suspect that resistor inertia is not as important as the time required for equilibration in the container (which is probably defined by convection in air). You may estimate this time, or you can use a resistor providing faster heating and turned off faster, so the heat generated in the resistor is the same. The losses will be smaller over this smaller time.
Your assumption that "the loss of energy from point one to point three es the same as that from three to five" does not seem right, as losses depend on the temperature.
