By the next code, we generate Tp1:

tempPV = (
  Three π^(2/3) + 6 6^(2/3) P π V^(2/3) - 
   6^(2/3) V^(
    2/3) (-3 + Sqrt[
      9 + (4 6^(2/3) π^(4/3) q^2)/(
       V^(4/3) β^2)]) β^2 + 
   Three 6^(2/3) V^(
    2/3) β^2 Log[
     1/6 (3 + Sqrt[
        9 + (4 6^(2/3) π^(4/3) q^2)/(V^(4/3) β^2)])])/(
  6 6^(1/3) π^(4/3) V^(1/3));

βin = 0.01;
βfi = 100;
βst = 0.005;
Desk[
  xlog[β] = Log[10, β]
  , {β, βin, βfi, βst}];

parap1 = {q -> 0.1, V4 -> 5000};
parap2 = {T2 -> 15, q -> 0.1, V2 -> 10000};
parap4 = {T4 -> 5, q -> 0.1, V4 -> 5000};

Desk[
  pressp2[β] = 
   P /. Clear up[(tempPV - T2 == 0) /. V -> V2 /. parap2, P][[1]];(*p1=
  p2*)
  pressp4[β] = 
   P /. Clear up[(tempPV - T4 == 0) /. V -> V4 /. parap4, P][[1]];(*p3=
  p4*)
  Tp1[β] = 
   T1 /. Clear up[(tempPV - T1 == 0) /. V -> V4 /. parap1 /. 
       P -> pressp2[β], T1][[1]];
  , {β, βin, βfi, βst}];

mi = Min[Table[Tp1[β], {β, βin, βfi, βst}]]
ma = Max[Table[Tp1[β], {β, βin, βfi, βst}]]

ListPlot[
 Table[{xlog[β], Tp1[β]}, {β, βin, βfi, βst}], 
 ScalingFunctions -> {Rescale[#, {mi, ma}, {0.`, 1.`}] &, 
   Rescale[#, {0.`, 1.`}, {mi, ma}] &}, Joined -> True, Body -> True,
  FrameStyle -> Black, 
 BaseStyle -> {FontSize -> 14, PrintPrecision -> 11}, 
 FrameLabel -> {"!(*SubscriptBox[(log), (10)]) (β)", 
   "!(*SubscriptBox[(T), (1)])"}, RotateLabel -> False, 
 PlotStyle -> {Blue, Thickness[0.006]}, 
 PlotRange -> {{-2, 2}, {mi, ma}}, Axes -> None, AspectRatio -> 0.8, 
 ImageSize -> 400, FrameTicks -> {{ticks, None}, {Automated, None}}] 

The result’s the next plot:

There’s a unusual fluctuation for $log_{10}^{beta}=1-2$. Correctly a easily lowering operate, what’s the origin of those fluctuations? Easy methods to repair this probably numerical error?