diff --git a/src/meas.rs b/src/meas.rs
index 7b24fc4..ebbce2e 100644
--- a/src/meas.rs
+++ b/src/meas.rs
@@ -56,7 +56,7 @@ impl<R: Region + Display + Sync> AbstractMeasurement for Current<R> {
     }
 }
 
-/// Mz
+/// M
 pub struct Magnetization(pub u32, pub u32);
 
 impl AbstractMeasurement for Magnetization {
@@ -66,23 +66,32 @@ impl AbstractMeasurement for Magnetization {
     }
 }
 
-/// Bz
+/// B
 pub struct MagneticFlux(pub u32, pub u32);
 
 impl AbstractMeasurement for MagneticFlux {
     fn eval(&self, state: &SimSnapshot) -> String {
         let b = state.get(self.0, self.1).b();
-        format!("Bz({}, {}): ({:.2e}, {:.2e}, {:.2e})", self.0, self.1, b.x(), b.y(), b.z())
+        format!("B({}, {}): ({:.2e}, {:.2e}, {:.2e})", self.0, self.1, b.x(), b.y(), b.z())
     }
 }
 
-/// Hz
+/// H
 pub struct MagneticStrength(pub u32, pub u32);
 
 impl AbstractMeasurement for MagneticStrength {
     fn eval(&self, state: &SimSnapshot) -> String {
         let h = state.get(self.0, self.1).h();
-        format!("Hz({}, {}): ({:.2e}, {:.2e}, {:.2e})", self.0, self.1, h.x(), h.y(), h.z())
+        format!("H({}, {}): ({:.2e}, {:.2e}, {:.2e})", self.0, self.1, h.x(), h.y(), h.z())
+    }
+}
+
+pub struct ElectricField(pub u32, pub u32);
+
+impl AbstractMeasurement for ElectricField {
+    fn eval(&self, state: &SimSnapshot) -> String {
+        let e = state.get(self.0, self.1).e();
+        format!("E({}, {}): ({:.2e}, {:.2e}, {:.2e})", self.0, self.1, e.x(), e.y(), e.z())
     }
 }
 
diff --git a/src/render.rs b/src/render.rs
index 43486ce..466b4b8 100644
--- a/src/render.rs
+++ b/src/render.rs
@@ -63,7 +63,7 @@ impl<'a> RenderSteps<'a> {
         let mut me = Self::new(state, measurements);
         me.render_scalar_field(10.0,  false, 2, |cell| cell.mat().conductivity().mag());
         me.render_scalar_field(100.0, true,  0, |cell| cell.mat().m().mag());
-        if true {
+        if false {
             me.render_b_z_field();
             me.render_e_xy_field();
         } else {
@@ -97,10 +97,10 @@ impl<'a> RenderSteps<'a> {
 
     //////////////   Bx/By/Ez configuration ////////////
     fn render_e_z_field(&mut self) {
-        self.render_scalar_field(100.0, true,  1, |cell| cell.e().z());
+        self.render_scalar_field(1e4, true,  1, |cell| cell.e().z());
     }
     fn render_b_xy_field(&mut self) {
-        self.render_vector_field(Rgb([0xff, 0xff, 0xff]), 1.0e-4, |cell| cell.b().xy());
+        self.render_vector_field(Rgb([0xff, 0xff, 0xff]), 1.0e-9, |cell| cell.b().xy());
     }
 
     fn render_vector_field<F: Fn(&Cell<mat::Static>) -> Point>(&mut self, color: Rgb<u8>, typical: Flt, measure: F) {
diff --git a/src/sim.rs b/src/sim.rs
index f2f4971..ac2ed95 100644
--- a/src/sim.rs
+++ b/src/sim.rs
@@ -256,7 +256,7 @@ impl<M: Material> Cell<M> {
         let delta_ex_y = inv_feature_size * (down.ex() - self.ex());
         let nabla_e = Vec3::from((delta_ez_y - delta_ey_z, delta_ex_z - delta_ez_x, delta_ey_x - delta_ex_y));
 
-        let delta_b = -nabla_e * delta_t;
+        let delta_b = -nabla_e * delta_t; // TODO: should scale delta_t by 2?
         let h = self.mat.step_h(&self.state, delta_b);
         Cell {
             state: CellState {