Answer / bunny

Suppose the range of process variable is
(0-150)PSI.So when the input is zero,the value in
instrument,say a transmiter connected to measure the
pressure,will shows 4mA.This is live zero.i.e,even if the
input is zero,output has some value.
Lets assume the instrument is faulty or the
power supply to the instrument is cuts off.Then it will
show zero reading.This is called dead zero.i.e,when the
instrument is faulty,it will shows the real zero value.

Answer / devendra_kushwaha27

Live Zero means 4MA
Dead Zero means below 4 MA

Answer / inzamam

When the working instrument shows zero as its output ....it is called as live zero........

When the instrument fails , thereby showing zero as their output , it is called as dead zero .

any one suggest me how to calculate percentage of air leakage with formula,

0 Answers   SSL,

---

what is the diffrene between DCS System and PLC System

5 Answers  

---

Can we use PLC in Hazardous Area?

2 Answers   MNHG,

---

if we have 450 mm heigth boiler drum level ,so what is span & zero value for a dpt tranmitter

4 Answers  

---

Capacitance, resistance ( colour coding ), parallel & series circuits.

0 Answers   CCIE,

---

role of electrical engineer in the instrumentation industry

1 Answers  

---

In apron feeder how TPH is calculated?

0 Answers   Lafarge,

---

give eg of how I/P is used in control loops

0 Answers   CEPC,

---

what is the daily job of an instrument commissioning supervisor

1 Answers   Petrofac,

---

what is cascade loop and how it work and why it used instead of PID single loop? In cascade, Which loop is faster and slower? Please explain with loop drawing and example...

2 Answers   Honeywell,

---

what is the principal of flow transmeter,level trans meter,presser transmeter?

11 Answers   Nestle, Reliance,

---

Which mechanical device is used in pressure gauges to reduce pulsating

4 Answers  

---