Answer / rajesh

pH is a measure of the acidity or basicity of a solution. pH
is a potentiometric measurement where the electrode used
produces an electrical signal which the pH meter converts to
a pH reading. The signal produced and measured is a voltage
and since voltage is a potential difference, two potentials
are needed to make a measurement:

a) The sensing electrode provides a potential proportional
to the logarithm of the hydrogen ion activity in the sample.
b) The reference electrode ideally provides a stable and
consistent potential independent of the activity of the sample.

The potential difference between the reference and sensing
electrode is measured by the meter and converted into a pH
value.

All pH sensors consist of a measuring glass electrode and
reference electrode. A combination electrode is an electrode
which contains both the reference and measuring electrode in
the one body. The reference electrode provides a constant
potential regardless of the composition of the solution it
is placed in. The voltage difference between the reference
and measuring electrodes is a function of the pH value of a
solution.

Calibration is done using pH Buffers. Most modern pH meters
are supplied with the facility for automatic buffer
recognition. The manufacturer will have programmed in a pH
versus temperature profile into memory for a specific type
of buffer. If a different buffer to that specified by the
manufacturer is used for calibration this will result in
calibration errors. For proper calibration, buffer solutions
of carefully selected accuracy and pH range are required.
The calibration should be performed using two buffers whose
values bracket the expected value of the samples being
measured. In practice many pH meters are equipped with auto
buffer recognition - this requires the use of the buffer
values specified by the meter manufacturer.

what is bevel? why bevel required in orifice plate?

2 Answers  

---

what is the difference between sensor and tranducers?

12 Answers  

---

how to calibrate the temprature transmitter MURCREYtype and thermocouple input type.

1 Answers   Shree Cement,

---

Explain the working of an enraf level gauge.

0 Answers  

---

Draw a simple circuit for a well head control panel used to protect the well against fire, leak, blockage, ESD, & controls the operation of one downhole & one surface safety valve. Explain the operation and controls

0 Answers  

---

---

plz send me general of ongc

0 Answers   ONGC,

---

what are the following documents comes under loopchecking

1 Answers   Heisco,

---

I want to measure flow by using DP Tx and range is 0 to 1200 Kg/cm2 ?

2 Answers  

---

what is difference between PLC and DCS?

10 Answers  

---

what is rtd

4 Answers   Petrofac,

---

what is Dry Leg calibration and where is it used

1 Answers   Petrofac,

---

hi sir yhis is zahid ali i am preparing for the jspl at oct.4.please send me the recently updated sample paper.

0 Answers   Jindal,

---