ECG ECG Equipment and Maintenance 1 — Questions and Answers
Question 1: What is the standard paper speed used for ECG recordings in the United States?
- 15 mm/sec
- 25 mm/sec (Correct answer)
- 50 mm/sec
- 100 mm/sec
Correct answer: 25 mm/sec
The standard ECG paper speed in the US is 25 mm/sec, which allows accurate measurement of intervals and waveforms.
Question 2: What voltage does each large square on ECG paper represent at standard calibration?
- 0.5 mV
- 1 mV (Correct answer)
- 2 mV
- 5 mV
Correct answer: 1 mV
At standard calibration (10 mm/mV), each large square (10 small squares tall) represents 1 mV of voltage.
Question 3: How often should ECG electrodes be replaced to ensure optimal signal quality?
- Every week
- Every month
- Per patient use (single-use) (Correct answer)
- Every 6 months
Correct answer: Per patient use (single-use)
Disposable ECG electrodes are single-use and should be replaced for each patient to prevent cross-contamination and ensure good conductivity.
Question 4: What is the function of the galvanometer in an ECG machine?
- Amplifies electrical signals
- Measures and records voltage differences (Correct answer)
- Filters artifact
- Stores patient data
Correct answer: Measures and records voltage differences
The galvanometer detects and records small voltage differences between electrodes, converting electrical activity into a visual tracing.
Question 5: Which filter setting on an ECG machine is used to reduce muscle artifact?
- High-pass filter
- Low-pass filter (Correct answer)
- Notch filter
- Band-pass filter
Correct answer: Low-pass filter
A low-pass filter cuts high-frequency signals such as muscle (EMG) artifact, producing a cleaner ECG tracing.
Question 6: What does the calibration pulse at the beginning of an ECG strip verify?
- Paper speed
- Correct lead placement
- 1 mV standardization mark (Correct answer)
- Battery level
Correct answer: 1 mV standardization mark
The calibration pulse (1 mV square wave, 10 mm tall) confirms the machine is set to standard sensitivity so tracings can be accurately interpreted.
ECG ECG Equipment and Maintenance 1
What is the standard paper speed used for ECG recordings in the United States?