This presentation focuses on the instruments that are used to measure parameters like temperature, pressure and pH in a bioreactor. Additionally you can get an idea on how the measurement is done along with their control.

1. INSTRUMENTATION, MEASUREMENT AND
CONTROL OF BIOPROCESS PARAMETERS
(TEMPERATURE, PRESSURE AND pH)
SLIDES PREPARED AND PRESENTED BY :
E. SHAFIKKAH PARVEEN
121011101441
III YEAR OF BIOTECHNOLOGY
2021-2025
UNIT IV: INSTRUMENTATION AND PROCESS CONTROL
XBT 602: PROCESS BIOTECHNOLOGY - UPSTREAM
SUBMITTED TO :
MS. P. MALA
ASST. PROFESSOR
DEPARTMENT OF BIOTECHNOLOGY
PMIST

2. CONTENTS
INSTRUMENTATION, MEASUREMENT AND CONTROL OF
TEMPERATURE
PRESSURE
pH

3. TEMPERATURE:
Since every organism used in a bioprocess has an
optimal growth temperature, it must be maintained
throughout the process. Therefore we consider
temperature as a parameter to be controlled during a
bioprocess.
It is a physical parameter

4. Instruments used:
For measuring temperature
Thermometer
Thermistor
Resistance Temperature Detector (RTD)
For heat control
Baffles
External jacket

5. Thermometer:
Presence of mercury indicates the
temperature
Most widely used
In large fermentors it is inserted
into the pockets provided in the
vessel of the reactor
Image source:
https://instrumentationtools.com/
liquid-in-glass-thermometer-
principle/

6. Thermistors:
These are semiconductors made from specific
mixtures of pure oxides of iron, nickel and other
metals,
Temperature is indicated by wheatstone bridge
Cheap and gives reproducible readings
Two types
PTC - positive temperature co-efficient thermistor
NTC- negative temperature co-efficient thermistor
Image source:
https://www.iqsdirectory.com/
articles/thermocouple/thermis
tors.html

7. The change in temperature produces a change in
the resistance.
This change enables us to detect the temperature
Resistance Temperature Detector (RTD):
Image source:
https://instrumentationtools.com/
components-of-rtd/

8. In fermentation, pressure influences the
solubility of gases and also help in maintaining
sterility
It is a physical parameter
PRESSURE:

9. Instruments used:
For measuring pressure:
Bourdon tube pressure gauge
Diaphragm-type pressure sensor
For controlling pressure:
Pressure reduction valve
Pressure retaining valve
Image source:
https://suku.de/en/product/567-
type-4310-bourdon-tube-
pressure-gauge-ns63-accuracy-
10-case-stainless-steel-
connection-brass.html
Image source:
https://tuckson.com/wp-
content/uploads/2020/08/tuckso
n-diaphragm-gauge.jpg

10. Standard pressure measuring sensor
Direct indication gauge
Inexpensive
Used for measuring the gauge pressure
of both gaseous and liquid fluids
Bourdon tube pressure gauge:
Image source:https://greenishco.com/PressureGauges

11. Used for low pressure measurement
Changes in pressure cause the
diaphragm capsule to move and these
movements are monitored by a
mechanically levered pointer
Diaphragm-type pressure sensor:
Image source:
https://instrumentationtools.com/pressure-gauges-
with-diaphragm-sensor-principle/

12. Controlled by valves namely pressure
reduction valve and pressure retaining
valve
Pressure reduction valves are present in
pipelines where it is necessary to reduce
the pressure and where the lower
pressure has to be maintained
Pressure retaining valve serves to retain
the temperature
Control of pressure:

13. It is necessary to maintain and control
the pH as it has an effect on the growth
of microorganism
It is a chemical parameter
pH:

14. Combination electrode:
The sensing element consists of a pair of
electrodes in contact with the liquid sample. One
of the electrodes is used as a reference, while the
other is sensitive to the pH of the sample. The pH
sensitive electrode (usually made of glass)
contains a buffer solution at a constant pH. The
glass behaves as a membrane that separates the
sample from the buffer solution; a potential
proportional to the pH difference is generated.
Instrument used for measuring:
Image source:
https://www.researchgate.net/figure/Schematic-
construction-plan-of-a-pH-combination-
electrode_fig1_11033770

15. pH is controlled and optimised by the
addition of acid and base with the
contents of the reaction
Control of pH:

16. MCQ’s

17. RTD
Baffles
External jacket
1.Which of the following is used to measure the temperature ?

18. RTD
Baffles
External jacket
1.Which of the following is used to measure the temperature ?

19. The tube
The scale
Mercury
2. Which indicates the temperature in a
thermometer ?

20. The tube
The scale
Mercury
2. Which indicates the temperature in a
thermometer ?

21. By DOE software
By valves
By gauges
3. How is pressured controlled ?

22. By DOE software
By valves
By gauges
3. How is pressured controlled ?

23. References :
https://www.slideshare.net/AATHILAKSHMIURUMA
NAT/temperature-measurement-and-control-in-
bioreactor-169774458
https://www.slideshare.net/AysvaryaGGanesan/bio
process-engineering-pressure-measurement-and-
control
PRINCIPLES OF FERMENTATION TECHNOLOGY-
P.E.Stanbury ,A. Whitaker and S.J.Hall

24. THANK YOU!