CLINICAL LAB EQUIPMENT REPAIR TECHNICIAN EXAM REVIEW
2026/2027 | HIGH-YIELD QUESTIONS & ANSWERS | KEY LAB
EQUIPMENT REPAIR & MAINTENANCE CONCEPTS | EXAM-STYLE
PRACTICE | DETAILED RATIONALES
Section 1: Laboratory Instrumentation Fundamentals (Questions
1–40)
Question 1
1. What is the primary function of a clinical chemistry analyzer?
A) To count blood cells
B) To measure the concentration of chemical analytes in blood, serum, plasma, or urine
C) To identify microorganisms
D) To analyze DNA sequences
Answer
Answer B: – To measure the concentration of chemical analytes in blood, serum, plasma, or
urine
Rationale
Clinical chemistry analyzers measure analytes such as glucose, electrolytes, enzymes, lipids, proteins,
and hormones. They use photometric, potentiometric, or other detection methods. Hematology
analyzers count cells; microbiology systems identify microorganisms; molecular systems analyze
DNA/RNA. ---
Question 2
2. Which detection method is most commonly used in chemistry analyzers for measuring
enzyme activity?
A) Turbidimetry
B) Photometry (absorbance)
C) Fluorometry
D) Potentiometry
,Answer
Answer B: – Photometry (absorbance)
Rationale
Enzyme activity is typically measured by monitoring the change in absorbance of a chromogenic
substrate over time. Photometry measures the amount of light absorbed by the reaction mixture, which
is proportional to the concentration of the product. ---
Question 3
3. What is the principle of operation for an ion-selective electrode (ISE) in an electrolyte
analyzer?
A) Light absorption
B) Potential difference measurement across a selective membrane
C) Light scattering
D) Electrical conductivity
Answer
Answer B: – Potential difference measurement across a selective membrane
Rationale
Ion-selective electrodes measure the potential difference between a reference electrode and a sensing
electrode with a membrane that selectively binds a specific ion (Na⁺, K⁺, Cl⁻, Ca²⁺). The potential is
proportional to the logarithm of the ion activity. ---
Question 4
4. What is the function of a peristaltic pump in a clinical chemistry analyzer?
A) To generate high pressure
B) To move liquids through tubing without contact between the fluid and pump components
C) To mix reagents
D) To control temperature
Answer
Answer B: – To move liquids through tubing without contact between the fluid and pump
components
,Rationale
Peristaltic pumps use rollers that compress a flexible tube, propelling fluid forward. This design
prevents contamination by isolating the fluid from pump components. They are widely used for sample
and reagent aspiration. ---
Question 5
5. Which of the following is a key component of a hematology analyzer?
A) Monochromator
B) Flow cytometer or impedance counter
C) Centrifuge
D) Incubator
Answer
Answer B: – Flow cytometer or impedance counter
Rationale
Hematology analyzers count and characterize blood cells using impedance (Coulter principle) or flow
cytometry (light scatter, fluorescence). The Coulter principle measures changes in electrical resistance
as cells pass through an aperture. ---
Question 6
6. What does a coagulation analyzer measure?
A) Red blood cell count
B) The time required for blood to clot
C) Hemoglobin concentration
D) White blood cell differential
Answer
Answer B: – The time required for blood to clot
Rationale
Coagulation analyzers measure clotting times, including Prothrombin Time (PT), Activated Partial
Thromboplastin Time (aPTT), and fibrinogen. They use mechanical or optical detection to determine
, the endpoint of clot formation. ---
Question 7
7. What is the principle of the Coulter counter (impedance) method?
A) Light scattering by cells
B) Change in electrical resistance as cells pass through an aperture
C) Fluorescence emission
D) Absorption of light by hemoglobin
Answer
Answer B: – Change in electrical resistance as cells pass through an aperture
Rationale
In the Coulter principle, cells suspended in an electrolyte pass through a small aperture. Each cell
displaces electrolyte, causing a momentary increase in electrical resistance, which is detected as a
voltage pulse proportional to cell volume. ---
Question 8
8. Which instrument is used to measure blood gases (pH, pCO₂, pO₂)?
A) Chemistry analyzer
B) Blood gas analyzer
C) Hematology analyzer
D) Coagulation analyzer
Answer
Answer B: – Blood gas analyzer
Rationale
Blood gas analyzers use electrochemical sensors (pH, pCO₂, pO₂ electrodes) to measure acid-base
status and respiratory function. Some also measure electrolytes, glucose, and lactate. ---
Question 9
2026/2027 | HIGH-YIELD QUESTIONS & ANSWERS | KEY LAB
EQUIPMENT REPAIR & MAINTENANCE CONCEPTS | EXAM-STYLE
PRACTICE | DETAILED RATIONALES
Section 1: Laboratory Instrumentation Fundamentals (Questions
1–40)
Question 1
1. What is the primary function of a clinical chemistry analyzer?
A) To count blood cells
B) To measure the concentration of chemical analytes in blood, serum, plasma, or urine
C) To identify microorganisms
D) To analyze DNA sequences
Answer
Answer B: – To measure the concentration of chemical analytes in blood, serum, plasma, or
urine
Rationale
Clinical chemistry analyzers measure analytes such as glucose, electrolytes, enzymes, lipids, proteins,
and hormones. They use photometric, potentiometric, or other detection methods. Hematology
analyzers count cells; microbiology systems identify microorganisms; molecular systems analyze
DNA/RNA. ---
Question 2
2. Which detection method is most commonly used in chemistry analyzers for measuring
enzyme activity?
A) Turbidimetry
B) Photometry (absorbance)
C) Fluorometry
D) Potentiometry
,Answer
Answer B: – Photometry (absorbance)
Rationale
Enzyme activity is typically measured by monitoring the change in absorbance of a chromogenic
substrate over time. Photometry measures the amount of light absorbed by the reaction mixture, which
is proportional to the concentration of the product. ---
Question 3
3. What is the principle of operation for an ion-selective electrode (ISE) in an electrolyte
analyzer?
A) Light absorption
B) Potential difference measurement across a selective membrane
C) Light scattering
D) Electrical conductivity
Answer
Answer B: – Potential difference measurement across a selective membrane
Rationale
Ion-selective electrodes measure the potential difference between a reference electrode and a sensing
electrode with a membrane that selectively binds a specific ion (Na⁺, K⁺, Cl⁻, Ca²⁺). The potential is
proportional to the logarithm of the ion activity. ---
Question 4
4. What is the function of a peristaltic pump in a clinical chemistry analyzer?
A) To generate high pressure
B) To move liquids through tubing without contact between the fluid and pump components
C) To mix reagents
D) To control temperature
Answer
Answer B: – To move liquids through tubing without contact between the fluid and pump
components
,Rationale
Peristaltic pumps use rollers that compress a flexible tube, propelling fluid forward. This design
prevents contamination by isolating the fluid from pump components. They are widely used for sample
and reagent aspiration. ---
Question 5
5. Which of the following is a key component of a hematology analyzer?
A) Monochromator
B) Flow cytometer or impedance counter
C) Centrifuge
D) Incubator
Answer
Answer B: – Flow cytometer or impedance counter
Rationale
Hematology analyzers count and characterize blood cells using impedance (Coulter principle) or flow
cytometry (light scatter, fluorescence). The Coulter principle measures changes in electrical resistance
as cells pass through an aperture. ---
Question 6
6. What does a coagulation analyzer measure?
A) Red blood cell count
B) The time required for blood to clot
C) Hemoglobin concentration
D) White blood cell differential
Answer
Answer B: – The time required for blood to clot
Rationale
Coagulation analyzers measure clotting times, including Prothrombin Time (PT), Activated Partial
Thromboplastin Time (aPTT), and fibrinogen. They use mechanical or optical detection to determine
, the endpoint of clot formation. ---
Question 7
7. What is the principle of the Coulter counter (impedance) method?
A) Light scattering by cells
B) Change in electrical resistance as cells pass through an aperture
C) Fluorescence emission
D) Absorption of light by hemoglobin
Answer
Answer B: – Change in electrical resistance as cells pass through an aperture
Rationale
In the Coulter principle, cells suspended in an electrolyte pass through a small aperture. Each cell
displaces electrolyte, causing a momentary increase in electrical resistance, which is detected as a
voltage pulse proportional to cell volume. ---
Question 8
8. Which instrument is used to measure blood gases (pH, pCO₂, pO₂)?
A) Chemistry analyzer
B) Blood gas analyzer
C) Hematology analyzer
D) Coagulation analyzer
Answer
Answer B: – Blood gas analyzer
Rationale
Blood gas analyzers use electrochemical sensors (pH, pCO₂, pO₂ electrodes) to measure acid-base
status and respiratory function. Some also measure electrolytes, glucose, and lactate. ---
Question 9
