Answer / carl_ellis

No, no, no.

A live zero is where the signal's value of zero engineering
units is an electrical signal value larger than zero.
For example, 4-20 mADC, 1-5 VDC, 10-50mV, etc., are all
examples of live zero. 4mA = 0 eng units. 1Vdc = 0 eng units.

On the other hand, a dead zero is where the signal's value
of zero engineering units is also zero electrical units.
0-20 mADC, 0-100 mV, 0-1Vdc, 0-5 Vdc, 0-5Aac are examples of
zero engineering units equaling zero electrical units.

0mA = 0 eng units; 0Vdc = 0 eng units

The value of a live zero is that zero electrical units
indicates a failed circuit; which could be lack of power, an
open circuit, a short circuit or failed signal source.

Neither live nor dead zero has an bearing on the linearity
or non-linearity of what the electrical signal represents.
Linearities are application specific.

Carl Ellis
Measure First

Answer / mugil

Dead zero: Dead Zero is below 4 ma.this is non linearity
Live Zero: Live Zero is 4ma.This is Linearity

Drum level tx with GP4 with zero elevation:7300mmh20 on HP and 8050mmh2o on LP as range but on commissioning the tx readiing is max,Why this reading?

0 Answers  

---

Why mmwc unit is used?

0 Answers  

---

what are the basic instructions used in simatic s7-300 plc?

5 Answers   Dr Reddys, HZL, Siemens,

---

What is passive connection of instrument in different types of IO module?

2 Answers  

---

Why we use the double acting control valve in flow line?

3 Answers  

---

What are the instrumental diagram of valve.

2 Answers   Karnataka Power,

---

what is transducer?

13 Answers   Sofcon,

---

is manifold required for an integral orifice meter?

2 Answers  

---

how to convert MA in to measuring values..and how mwasuring values into MA ?..plz ansr.i have intervw

0 Answers  

---

what is span value and zero ? and how set ?

0 Answers  

---

We have ZR22G-100-S-A-E-T-T--E-A/CV/F1 Model Zirconia Oxygen analyser which is Yokogawa make. I kept the analyser in Flue gas path at Air pre heater area. My plant is 7.5MW Biomass power plant. For a particular fuel, Coconut Husk which contains Sodium and Potassium chlorides iam not getting proper reading, Analyser output always Zero. I calibrated the analyser and it is OK. For Other fuels like Wood chips, Cholam waste, DOB, Groundnutshells, Ply wood waste and all iam getting actual percentage of Oxygen. What is the main reason behind this draw back?

2 Answers  

---

What is actuator what is motorized control valve?

5 Answers   Emco,

---