CERTIFIED HEMODIALYSIS BIO-MEDICAL TECHNICIAN (CHBT) - FULL COLLECTION OF EXAM QUESTIONS WITH ACCURATE ANSWERS

1. The maximum allowable bacteria count in dialysate according to AAMI
standards is:
o a) 100 CFU/mL
o b) 200 CFU/mL
o c) 500 CFU/mL
o d) 1000 CFU/mL ANSWER : b) 200 CFU/mL
2. Endotoxin levels in dialysate must not exceed:
o a) 0.25 EU/mL
o b) 0.5 EU/mL
o c) 1.0 EU/mL
o d) 2.0 EU/mL ANSWER : b) 0.5 EU/mL
3. Reverse osmosis membrane rejection rate should be at least:
o a) 85%
o b) 90%
o c) 95%
o d) 99% ANSWER : c) 95%
4. Carbon tanks in water treatment remove:
o a) Bacteria only
o b) Chlorine and chloramines
o c) Calcium and magnesium
o d) Sodium only ANSWER : b) Chlorine and chloramines
5. Water softener resin removes:
o a) Chlorine
o b) Bacteria
o c) Calcium and magnesium
o d) Endotoxins ANSWER : c) Calcium and magnesium
6. The recommended water temperature entering the RO system is:
o a) 40-50°F
o b) 60-70°F
o c) 77-86°F
o d) 90-100°F ANSWER : c) 77-86°F
7. Total chlorine levels in product water should not exceed:
o a) 0.1 ppm

, o b) 0.5 ppm
o c) 1.0 ppm
o d) 2.0 ppm ANSWER : a) 0.1 ppm
8. Hardness in product water should be less than:
o a) 1 ppm
o b) 5 ppm
o c) 10 ppm
o d) 15 ppm ANSWER : b) 5 ppm
9. Pre-filter micron rating typically used before RO membranes:
o a) 1 micron
o b) 5 microns
o c) 10 microns
o d) 20 microns ANSWER : b) 5 microns
10.RO membrane differential pressure alarm typically activates at:
o a) 10 psi
o b) 20 psi
o c) 30 psi
o d) 40 psi ANSWER : c) 30 psi
11.Acceptable pH range for product water:
o a) 5.0-6.0
o b) 6.5-7.5
o c) 7.0-8.0
o d) 8.0-9.0 ANSWER : b) 6.5-7.5
12.The conductivity of product water should not exceed:
o a) 1 µS/cm
o b) 5 µS/cm
o c) 10 µS/cm
o d) 20 µS/cm ANSWER : c) 10 µS/cm
13.Sediment filters should be changed:
o a) Weekly
o b) Monthly
o c) Every 3-6 months or per manufacturer specifications
o d) Annually ANSWER : c) Every 3-6 months or per
manufacturer specifications
14.Carbon tank regeneration uses:
o a) Acid
o b) Salt brine
o c) Citric acid
o d) Backwash with water ANSWER : d) Backwash with water
15.Water softener regeneration uses:
o a) Sodium chloride brine
o b) Citric acid
o c) Peracetic acid

, o d) Bleach ANSWER : a) Sodium chloride brine
16.Ultraviolet (UV) light systems destroy:
o a) Hardness
o b) Chlorine
o c) Bacteria
o d) Endotoxins ANSWER : c) Bacteria
17.RO reject water percentage typically ranges from:
o a) 10-20%
o b) 20-30%
o c) 25-40%
o d) 50-60% ANSWER : c) 25-40%
18.Deionization (DI) tanks remove:
o a) Bacteria
o b) Dissolved ionic contaminants
o c) Particulate matter
o d) Organic compounds ANSWER : b) Dissolved ionic
contaminants
19.Chemical disinfection of the water system should be performed:
o a) Daily
o b) Weekly
o c) Monthly or as needed
o d) Annually ANSWER : c) Monthly or as needed
20.Maximum aluminum level in product water:
o a) 1 µg/L
o b) 5 µg/L
o c) 10 µg/L
o d) 50 µg/L ANSWER : c) 10 µg/L
21.Fluoride level in product water must not exceed:
o a) 0.1 mg/L
o b) 0.2 mg/L
o c) 0.5 mg/L
o d) 1.0 mg/L ANSWER : b) 0.2 mg/L
22.The purpose of a pressure-sustaining valve in an RO system:
o a) Increases water temperature
o b) Maintains back pressure on membrane
o c) Removes bacteria
o d) Filters particulates ANSWER : b) Maintains back pressure
on membrane
23.Heat disinfection temperature for water distribution systems:
o a) 100°F
o b) 120°F
o c) 160°F or higher
o d) 212°F ANSWER : c) 160°F or higher

, 24.Bacterial culture samples should be obtained from the water system:
o a) Daily
o b) Weekly
o c) Monthly
o d) Quarterly ANSWER : c) Monthly
25.Maximum copper level in product water:
o a) 0.01 mg/L
o b) 0.1 mg/L
o c) 0.5 mg/L
o d) 1.0 mg/L ANSWER : b) 0.1 mg/L
26.Booster pumps in water systems are used to:
o a) Remove bacteria
o b) Increase water pressure
o c) Heat the water
o d) Filter particles ANSWER : b) Increase water pressure
27.Dead legs in water distribution systems should not exceed:
o a) 6 inches
o b) 12 inches
o c) 18 inches
o d) 24 inches ANSWER : a) 6 inches
28.Peracetic acid is used for:
o a) Water softening
o b) System disinfection
o c) Removing hardness
o d) Filtering water ANSWER : b) System disinfection
29.RO membrane life expectancy is typically:
o a) 6 months
o b) 1 year
o c) 2-3 years
o d) 5 years ANSWER : c) 2-3 years
30.Inlet water pressure to the dialysis machine should be:
o a) 10-20 psi
o b) 20-40 psi
o c) 40-80 psi
o d) 80-100 psi ANSWER : c) 40-80 psi
31.Total dissolved solids (TDS) in feed water affects:
o a) Water temperature only
o b) RO membrane performance
o c) Patient blood pressure
o d) Dialyzer efficiency only ANSWER : b) RO membrane
performance
32.The purpose of an air gap in drain lines:
o a) Increases flow rate