Citizen CH-650 Digital Blood Pressure Monitor Instruction Manual

Overview

The CH-650 Digital Blood Pressure Monitor is a compact wrist-style device for adults who want to check systolic blood pressure, diastolic blood pressure, and pulse rate at home. It uses the oscillometric measurement method and automatically inflates the wrist cuff with an internal pump.

This monitor is intended to support personal health tracking under medical guidance. It is not a diagnostic instrument, and a single reading should not be used to change medication or determine treatment. Record measurements over time and discuss concerning results with a physician.

Specifications

• Model: CH-650
• Measurement method: Oscillometric
• Measurement location: Wrist
• Suitable wrist circumference: 13.5 to 21.5 cm
• Pressure measurement range: 0 to 280 mmHg
• Pulse measurement range: 40 to 180 beats per minute
• Pressure accuracy: ±3 mmHg
• Pulse accuracy: ±5% of the displayed reading
• Power supply: Two AAA alkaline batteries
• Rated voltage: 3 V DC
• Memory capacity: Up to 60 measurement results
• Automatic power-off: Approximately 3 minutes after the last operation
• Operating temperature: 10°C to 40°C
• Operating humidity: 30% to 85% relative humidity
• Storage temperature: -20°C to 60°C
• Storage humidity: 10% to 95% relative humidity
• Dimensions: 65 mm wide × 74 mm high × 29 mm deep
• Weight: Approximately 103 g without batteries
• Protection: Type BF applied part; IPX0 water protection classification
• Service life: 5 years

Package Contents

• CH-650 blood pressure monitor
• Wrist cuff
• Storage case
• Two AAA batteries
• Instruction manual

Detailed Description

The monitor is designed to be worn on the inside of the wrist. During a reading, the cuff inflates automatically and detects pressure changes caused by the pulse. The display then shows the upper systolic value, lower diastolic value, and pulse rate.

The main controls are the START/STOP switch and the MEMORY switch. The display also includes a battery level indicator, a body movement indicator, and an irregular heartbeat indicator.

• START/STOP switch: Starts or ends a measurement and can quickly release cuff pressure.
• MEMORY switch: Recalls stored readings, beginning with the most recent result.
• Systolic display: Shows pressure when the heart contracts and pumps blood.
• Diastolic display: Shows pressure while the heart relaxes between beats.
• Pulse display: Shows the detected heart rate in beats per minute.
• Body Movement indicator: Signals that wrist or hand movement may have affected the result.
• Irregular Heartbeat indicator: Appears when the detected heartbeat pattern varies significantly during measurement.
• Battery indicator: Warns when the batteries need replacement.

Safety

• Consult a physician before use if you have heart disease, high blood pressure, circulatory problems, a pacemaker, severe arm circulation problems, or a known irregular heartbeat.
• Do not use the cuff on an injured wrist or on a wrist receiving an intravenous infusion or blood transfusion.
• Do not use the monitor on infants or newborns. The device is intended for adults.
• Do not use the monitor near flammable anesthetic gases or in oxygen-enriched environments.
• Keep mobile phones and other potential sources of electromagnetic interference away from the monitor during use.
• If the cuff feels abnormally tight or another irregularity occurs, stop the monitor immediately or remove the batteries.
• Stop using the monitor and seek medical advice if a reading seems abnormal or measurement makes you feel unwell.
• Do not take repeated readings without a pause. Allow approximately one minute between measurements to reduce congestion or swelling and improve reliability.
• Do not alter medication dosage based on a self-measured result.
• Use the monitor only for blood pressure and pulse measurement.
• Use only approved parts and accessories.

Preparing for a Measurement

For more consistent results, measure at roughly the same time each day and use the same wrist whenever possible. Blood pressure changes naturally with posture, activity, stress, sleep, food, temperature, and time of day.

• Urinate before measuring if necessary.
• Rest quietly for 10 to 15 minutes before taking a reading.
• Avoid exercise, eating, smoking, coffee, and tea immediately before measurement.
• Do not measure immediately after bathing or drinking.
• Measure in a comfortable room, ideally around 20°C. Avoid measurement below 10°C or above 40°C.
• Take several deep breaths and relax before starting.
• Remain quiet and still throughout the measurement.

Setup

Installing the Batteries

1. Press down on the battery cover and slide it in the direction of the arrow to remove it.
2. Insert two AAA alkaline batteries, observing the positive and negative markings. Insert each battery with the negative side first, beginning with the battery nearest the display.
3. Slide the battery cover back into position until it clicks.

Replace both batteries together when the battery symbol appears or the display remains blank. Use alkaline batteries only. Do not combine alkaline and manganese batteries, and do not use rechargeable batteries.

Attaching the Wrist Cuff

1. Open the cuff and place it around the bare left wrist.
2. Position the monitor on the inside of the wrist.
3. Place the upper edge of the cuff approximately 1 to 2 cm from the wrist crease.
4. Pull the cuff end to make it snug without excessive tightness.
5. Fasten the hook-and-loop closure securely.

The cuff fits wrists measuring 13.5 to 21.5 cm. A cuff that is too loose or too tight can produce an incorrect result. The right wrist may also be used, but readings can differ between wrists, so use the same wrist for regular tracking.

Measuring Blood Pressure

1. Apply the wrist cuff as described above.
2. Sit upright with your back supported and relax your hand and fingers.
3. Turn the palm upward and keep the cuff at heart level. Place a folded towel or similar support under the arm if needed.
4. Do not clench your fist, move your wrist, change the monitor position, or talk.
5. Press the START/STOP switch.
6. Wait while the cuff inflates and the monitor completes the reading.
7. Read the displayed systolic pressure, diastolic pressure, and pulse rate.
8. Press START/STOP to turn the monitor off, or allow the automatic power-off function to switch it off after approximately three minutes.

The initial display confirms that the monitor is operating. A pulse symbol appears when the device detects a pulse. If the body movement indicator appears, repeat the measurement while remaining completely still. If the irregular heartbeat indicator appears, relax and repeat the reading. Frequent appearances should be discussed with a physician.

Memory and Average Readings

The CH-650 stores up to 60 measurement results. Each stored result receives a data number, with the most recent result identified as number 1.

1. Press the MEMORY switch to enter the memory display.
2. Press the switch repeatedly to view results from the newest to the oldest.
3. When three or more results are stored, the monitor can display the average of the most recent three readings. The average is marked as “3A.”

The three-reading average is not shown when fewer than three measurements are available.

Deleting Stored Results

1. Press the MEMORY switch.
2. While holding MEMORY, press and hold START/STOP for more than three seconds.
3. Continue until the display confirms that the stored data has been deleted.

Deleting the memory removes all stored measurement results rather than a single selected entry.

Cleaning and Maintenance

• Store the monitor in its case away from direct sunlight, dust, children, pets, and pests.
• Do not expose the device to temperatures above 60°C, below -20°C, or humidity above 95% during storage.
• Do not drop the monitor or subject it to strong vibration.
• Remove the batteries if the monitor will not be used for an extended period.
• Do not disassemble or modify the device.
• Clean a dirty monitor with a cloth lightly moistened with sterilizing alcohol or neutral detergent, then wipe it dry.
• Clean the cuff with a damp cloth and avoid vigorous rubbing, which can cause air leakage.
• Never clean the monitor with thinner or benzene.
• For continued performance, inspection approximately every two years is generally recommended.
• Dispose of used batteries and the monitor according to applicable local recycling and electronic-waste requirements.

Troubleshooting

The Display Is Blank

• Replace both batteries with new alkaline batteries.
• Check that the batteries are installed with the correct polarity.

A Measurement Will Not Start

• Confirm that the cuff is attached correctly and fits within the supported wrist circumference.
• Check whether the measurement symbol appears.
• Remain calm and still during the reading.
• Be aware that measurement may be difficult with a very weak pulse or certain cardiac arrhythmias.

The Cuff or Movement Indicator Appears

• Wrap the cuff snugly and position it on the inside of the wrist.
• Keep the cuff at heart level.
• Do not move, speak, clench the fist, or alter the monitor position.
• Repeat the measurement after relaxing.

The Pulse Is Outside the Measuring Range

If the detected pulse is below 39 beats per minute or above 181 beats per minute, reapply the cuff, take several deep breaths, and repeat the measurement. If the condition continues, consult a physician.

Readings Seem Unusually High or Low

Check the cuff position, body posture, room temperature, recent activity, food, drinks, smoking, stress, and rest period. Repeat the reading after remaining relaxed for several minutes. Compare trends over multiple readings rather than relying on one result.

The Monitor Still Does Not Work

Remove the batteries, install new batteries, and try again. If the monitor continues to malfunction, discontinue use and arrange appropriate service through the retailer or service organization from which the device was obtained.

Understanding Blood Pressure Readings

Systolic pressure is the higher value produced when the heart contracts. Diastolic pressure is the lower value recorded while the heart relaxes. Both values change throughout the day in response to activity, posture, emotional state, sleep, temperature, and other conditions.

Home measurements can be useful because they are taken in a familiar setting, but readings should be interpreted with a physician. Measure consistently, maintain a written or electronic record, and focus on long-term patterns instead of one isolated result.

Pros and Cons

Pros

• Compact wrist design for convenient home monitoring.
• Automatic inflation and one-touch measurement operation.
• Stores up to 60 readings and calculates a recent three-reading average.
• Displays blood pressure and pulse together.
• Provides movement and irregular-heartbeat indicators.
• Includes a storage case and automatic power-off feature.

Cons

• Correct wrist position and heart-level support are essential for reliable readings.
• Results can be affected by movement, stress, recent activity, food, drinks, and temperature.
• The device is not intended to diagnose conditions or replace professional medical advice.
• People with weak pulses, arrhythmias, or serious circulation problems may not obtain a measurement.
• The monitor is not water resistant and should be kept dry.