Intro to Analyzers and Terminology

Question 1

What is analysis?

Answer 1

Quantitative or qualitative determination of constituent parts. The determination of chemical components or intrinsic physical properties of a mixture

Question 2

Define qualitative Analysis

Answer 2

The determination of WHAT is in the sample e.g. a gas chromatograph determines there is propane present in a gas

Question 3

Define quantitative analysis

Answer 3

The determination of HOW MUCH is in a certain sample e.g. a gas chromatograph determines that propane represents 19% of a gas in the sample volume

Question 4

What is an analyzer

Answer 4

An instrumentation device that the continuously monitors a process stream unattended.

A measurement system can determine:

a) Chemical composition; provide one or more quantitative analysis of component
b) Physical properties; boiling point, vapor pressure, and pour point

Question 5

What is a process analyzer

Answer 5

Analyzers for process fluids that generally have a higher expected concentration

Question 6

What is a compliance analyzer

Answer 6

An analyzer for low values of concentration.
This can be:

An emission monitor; does not measure process but rather monitors smoke stacks, wastewater or ambient air

Safety monitor; gives warnings about hazardous conditions in the workplace such as presence of H2S

Question 7

Define grab sample

Answer 7

A process sample that is manually taken out of the process and is transferred to an analyzer.

Question 8

What are the three characteristics of an on-line analyzer?

Answer 8

1) Connected to a process in order to obtain a sample
2) Actively measuring
3) Actively sending data

Question 9

State five ways that analyzers can have a positive impact on plant operations.

Answer 9

1) Ensure product quality
2) Reduce downtime
3) warn of hazardous atmospheres
4) Reduce emissions
5) Lower operating costs

Question 10

What is the main disadvantage of having a sensor installed at a distance away from the process?

Answer 10

The ambient temperature can greatly effect the sample during transport

Question 11

_________ is also another way to describe a sensor that is “in-line”.

Answer 11

in-situ

Question 12

While in use, is a personal safety monitor considered on-line?

Answer 12

Yes as it’s:
1) Is constantly monitoring the ambient air
2) Actively measuring
3) Actively sending quantitative data about the atmosphere

Question 13

Briefly describe calibration of an analyzer by use of the standard sample method.

Answer 13

Standard sample method involves taking the analyzer offline, taking a gas mixture with known concentration (standard) and then adjusting the zero and the span of the analyzer (two point calibration).

Question 14

Describe calibration of an analyzer by use of the paired sample method.

Answer 14

A grab sample is analyzed offline in a lab and the results are then used to calibrate the analyzer online. The time of grab sample needs to be taken into account as process can change over time.

Question 15

Describe the characteristics of an ideal zero gas for setting an analyzer to zero.

Answer 15

An ideal zero gas will be devoid of the substance that trips the analyzer in order to get a zero reading.

Question 16

Can IAS be used as zero gas for a CO2 analyzer?

Answer 16

Since IAS contains some CO2 ppm it would need to be passed through an activated charcoal filter.

Question 17

What is absolute standardization method?

Answer 17

The analyzer calibrates itself by simulating zero and span properties.

Question 18

After the lab result, it is determined that the online fluoride ion
analyzer should be calibrated using calibration solution. This
is _________.

Answer 18

Standard Sample Method

Question 19

How are gas mixtures that offer the highest level of accuracy prepared and what are they
called?

Answer 19

Primary Standard gas mixtures are prepared gravimetrically meaning that every component is weighed on a special analytical balance.

Question 20

Why can’t some gasses be mixed no matter what the cylinder pressure is?

Answer 20

1) Reactivity with other components
2) Reactivity with the container
3) Flammability

Question 21

Mixtures of flammable gas and air to be stored in high pressure cylinders may be
prepared if what condition is followed?

Answer 21

50% or less of the flammable gas LEL

Question 22

List 3 sample conditions that are needed to calibrate a composition analyzer.

Answer 22

1) Temperature
2) Pressure
3) Flow rate
4) Phase

Question 23

What makes an ideal span gas?

Answer 23

A gas made of the same concentrations as expected in the process but all components and concentrations are known exactly.