diff --git a/succbone/succd/http.go b/succbone/succd/http.go
index 506236b..0d1ce02 100644
--- a/succbone/succd/http.go
+++ b/succbone/succd/http.go
@@ -36,24 +36,6 @@ func formatVolts(v float32) string {
 	return fmt.Sprintf("%.4f V", v)
 }
 
-// formatMbar formats a millibar value using scientific notation and returns a
-// HTML fragment (for superscript support).
-func formatMbar(v float32) template.HTML {
-	exp := 0
-	for v < 1 {
-		v *= 10
-		exp -= 1
-	}
-	for v >= 10 {
-		v /= 10
-		exp += 1
-	}
-	res := fmt.Sprintf("%.3f", v)
-	res += fmt.Sprintf(" x 10<sup>%d</sup>", exp)
-	res += " mbar"
-	return template.HTML(res)
-}
-
 // apiData is the data model served to the user via HTTP/WebSockets
 type apiData struct {
 	// Safety interlocks.
@@ -125,7 +107,7 @@ func (s *webServer) apiData(skipSystem bool) *apiData {
 	ad.Safety.Failsafe = state.safety.failsafe
 	ad.Safety.HighPressure = state.safety.highPressure
 	ad.Pirani.Volts = formatVolts(volts)
-	ad.Pirani.Mbar = formatMbar(mbar)
+	ad.Pirani.Mbar = formatMbarHTML(mbar)
 	ad.Pirani.MbarFloat = mbar
 	ad.Pumps.RPOn = state.rpOn
 	ad.Pumps.DPOn = state.dpOn
diff --git a/succbone/succd/process.go b/succbone/succd/process.go
index a62c261..f19dc5e 100644
--- a/succbone/succd/process.go
+++ b/succbone/succd/process.go
@@ -78,11 +78,11 @@ func (d *daemon) processOnce(_ context.Context) error {
 			d.safety.failsafe = true
 			klog.Errorf("Pirani probe seems disconnected; enabling failsafe mode")
 		}
-	} else {
+	} else if d.piraniDetection() == piraniDetectionConnected {
 		if d.safety.failsafe {
 			if mbar >= 1e2 {
 				d.safety.failsafe = false
-				klog.Infof("Values are plausible again; quitting failsafe mode")
+				klog.Infof("Pirani probe value (%s) is plausible again; quitting failsafe mode", formatMbar(mbar))
 			}
 		}
 	}
@@ -90,12 +90,12 @@ func (d *daemon) processOnce(_ context.Context) error {
 	if mbar >= 1e-1 {
 		if !d.safety.highPressure {
 			d.safety.highPressure = true
-			klog.Errorf("Pressure is too high; enabling diffusion pump lockout")
+			klog.Errorf("Pressure is too high (%s mbar); enabling diffusion pump lockout", formatMbar(mbar))
 		}
 	} else if mbar < (1e-1)-(1e-2) {
 		if d.safety.highPressure {
 			d.safety.highPressure = false
-			klog.Infof("Pressure is low enough for diffusion pump operation; quitting diffusion pump lockout")
+			klog.Infof("Pressure is low enough (%s mbar) for diffusion pump operation; quitting diffusion pump lockout", formatMbar(mbar))
 		}
 	}
 
diff --git a/succbone/succd/scientific.go b/succbone/succd/scientific.go
index d2df8d8..a15f273 100644
--- a/succbone/succd/scientific.go
+++ b/succbone/succd/scientific.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"html/template"
 	"strconv"
 )
 
@@ -16,8 +17,25 @@ func (s *ScientificNotationValue) UnmarshalText(text []byte) error {
 	return nil
 }
 
-func (s *ScientificNotationValue) MarshalText() ([]byte, error) {
-	v := float64(*s)
+// formatMbarHTML formats a millibar value using scientific notation and returns
+// a HTML fragment (for superscript support).
+func formatMbarHTML(v float32) template.HTML {
+	exp := 0
+	for v < 1 {
+		v *= 10
+		exp -= 1
+	}
+	for v >= 10 {
+		v /= 10
+		exp += 1
+	}
+	res := fmt.Sprintf("%.3f", v)
+	res += fmt.Sprintf(" x 10<sup>%d</sup>", exp)
+	res += " mbar"
+	return template.HTML(res)
+}
+
+func formatMbar(v float32) string {
 	exp := 0
 	for v < 1 {
 		v *= 10
@@ -29,5 +47,11 @@ func (s *ScientificNotationValue) MarshalText() ([]byte, error) {
 	}
 	res := fmt.Sprintf("%.3f", v)
 	res += fmt.Sprintf("e%d", exp)
+	return res
+}
+
+func (s *ScientificNotationValue) MarshalText() ([]byte, error) {
+	v := float32(*s)
+	res := formatMbar(v)
 	return []byte(res), nil
 }