Citizen CTD 504 Ear Thermometer Instruction Manual

Citizen CTD 504



Model: CTD 504

PARTS NAMES / Display Symbols

Display Symbols

PRECAUTIONS (Intended Use)

  1. The CTD504 is a clinical electronic thermometer that uses an infrared sensor to
    detect the body temperature of people of any age from the auditory canal in a
    home setting.
  2. Do not use the CTD504 as a replacement for medical advice. Consult your
    doctor if you have any concerns.
  3. ONLY the CTD504 probe tip is waterproof. Do not immerse it in water or any other liquid.
  4. Do not drop the CTD504, and avoid any strong impact.
  5. Do not use the CTD504 on any body part other than your ear.
  6. Do not move or shake your body while measuring.
  7. Do not use for any purpose other than the intended use. The manufacturer is not
    liable for misuse.
  8. The CTD504 can measure up to six times a day. To know your normal body
    temperature range, we suggest you measure regularly.
  9. If any damage occurs to the sensor inside the probe tip or to the unit itself,
    return the product to your local distributor.
  10. Keep the CTD504 away from children. Do not let them use the CTD504 on their
    own. They may choke on the battery or tiny component parts by accident.
  11. Install a new CR2032 lithium battery when the power is low. Use of any other
    battery may lead to inaccurate results or malfunction.
  12. Without regular recalibration, the results may not be accurate. Every CTD504 is
    calibrated right after production. See “Warranty and Recalibration” for details.
  13. Keep the CTD504 away from sunlight and dusty places.

Important Notice:
The CTD504 does not require a probe cover during use. It is important to
clean and disinfect the CTD504 before and after each use. See “Cleaning and
Disinfection” for details.
For measurement:

  • When asleep, pressure on the ear may cause higher-than-normal temperature. Wait a few minutes, and then measure again.
  • Clean your external ear before measuring. To ensure an accurate result, keep your ear free from obstructions or excess earwax.
  • The measuring results from the left and right ears may differ slightly. We recommend measuring in the same ear.
  • Before measuring, the user and the CTD504 should be in a steady room temperature for at least 30 minutes. The user should also rest for 30 minutes after exercising.


  1. Press the |/O button. The LCD screen displays all digital segments.
  2. If the CTD504 has saved past results, the LCD screen automatically displays the latest result.
LCD screen

3. When C or F fl ashes with a short beep, the CTD504 is ready to use.

  1. To improve accuracy, follow the illustrations below. For adults, pull the ear up and back. For infants and children, pull the ear back.
pull the ear back

2. Fit the probe tip into the ear canal, and then press the START button. Release the button and wait a few seconds until you hear a long beep.

Fit the probe

3. Take the CTD504 out of the ear canal. The LCD displays the latest measuring result. Without any operation, the CTD504 automatically shuts off after 1 minute.

Note: Before re-measurement, wait 1 – 3 minutes.




  • BATTERY flashes: You can still measure, but the accuracy may not impaired.
  • BATTERY lights or no reaction at all: Change the battery as soon as possible.

Note: Change the battery away from small children and any source of heat.

  1. Press the upper part of the battery cap to unlock it.Insert the tip of a tool into the gap at the side of the battery compartment. Remove the worn-out battery.
  2. Insert a new CR2032 lithium battery into the CTD504, according to the polarities in the figure. Push it firmly into place with a “click”, then replace the cap.


The CTD504 does not require a probe cover during use. Clean and disinfect the
CTD504 before and after each use. If you wish to share the CTD504 with others,
follow the instructions below.


  1. Cotton bud: Available in supermarkets.
  2. 70 % concentration alcohol swab: Available in supermarkets.

Note: Dispose of used cotton buds and alcohol swabs in accordance with local regulations.

Cleaning : Probe area

Use a clean cotton bud to wipe off any visible dirt or ear wax. Gently wipe the area

Note: The most delicate and sensitive part of the CTD504 is the sensor inside the
probe tip. Poking it with force may cause damage to the CTD504. When cleaning,
take extra care.

Hold the CTD504 facing down to prevent water getting into the CTD504. Use an
alcohol swab to clean the probe area in a circular motion for 15 seconds (around 20

DISINFECTION (Probe & Exterior Area)

  1. Hold the CTD504 facing down to prevent water getting into the CTD504. Use an alcohol swab to clean the probe area in a circular motion for 15 seconds (around 20 times).
  2. Then, use the same alcohol swab to wipe the exterior area back and forth for another 15 seconds (around 20 times).
  3. Wait at least 30 seconds until the CTD504 is completely dry.

Continue to set units on the next page, and start measuring. Repeat the steps above when measurement is done.

Do not use detergent or any strong chemicals on the CTD504.

The CTD504 has a built-in “Fever Alert” feature. If you have a fever between 37.5 °C – 43.0 °C (99.5 °F – 109.4 °F), the “Fever Alert” function will inform you by a fl ashing result, red LED backlight, and a series of beeps.
Do not use the CTD504 as a replacement for medical advice. Consult your doctor if
you have any concerns.



  1. If you will not use the CTD504 for over 2 months, remove the battery from the
  2. Always store the CTD504 in its container after use.
  3. ONLY the CTD504 probe tip is waterproof. Do not dip it in water or any other
  4. Keep the CTD504 away from:
    • Extreme temperatures
    • Overly humid or dry environment
    • Direct sunlight
    • Dusty places.
  5. For details of environmental conditions, refer to “Specifi cations”. Using the
    CTD504 outside the stated range may lead to inaccurate results or malfunction.


  1. Do not disassemble or change any parts of the CTD504. Such action may
    reduce its accuracy.
  2. Do not drop the CTD504, and avoid any strong impact.


Normal body temperature differs by body parts, time and age. Here are two tables
for your reference:

  1. Normal Body Temperature Range
Normal Body Temperature Range

Source: Offi cial Health Central, http://www.offi

2. Figure: Diurnal Variations in Body Temperature

Diurnal Variations in Body Temperature

Source: 1911, Encyclopedia Britannica, 11th edition, Volume 2, Part 1, Slice 1, p95.




This product conforms to the provisions of the EC directive
93/42/EEC (Medical Device Directive). And also complies
with following standards (included but not limited):
Safety standard:
EN 60601-1 Medical electrical equipment part 1: General requirements for safety
EMC standard:
EN 60601-1-2 Medical electrical equipment part 1-2: General requirements for
safety- Collateral standard: Electromagnetic compatibility- Requirements and tests
Performance standards:
EN 12470-5, Clinical thermometers – Part 5: Performance of infra-red ear
thermometers (with maximum device)

Follow instructions for use.

Follow instructions for use.
BF Classification

Warranty & Recalibration
Warranty For One Year from Manufacturing Date
CITIZEN SYSTEMS JAPAN Co., Ltd. grants a 1 year warranty on the product
commencing on the date of purchase. Within the limited time, we will eliminate any
defects in the appliance resulting from faults in the material or workmanship free of

Please note that this service does not cover damage caused by misuse or abuse;
accident; the attachment of any unauthorized accessory; alteration to the product;
improper installation; unauthorized repairs or modifi cation; improper use of
electrical/power supply; loss of power; dropped product; malfunction or damage
of an operation part due to failure to provide the manufacturer’s recommended
maintenance; transportation damage; theft; neglect; vandalism; or environmental
conditions; loss of use during the period the product is at a repair facility or
otherwise awaiting parts or repair; or any other conditions whatsoever that are
beyond the control of the importers or distributors.

Recalibration Notice
Every CTD504 is properly calibrated right after production. We recommend that USERs bring the CTD504 to certain laboratories every 2 years for proper recalibration. The CTD504 does not need periodic recalibration, if the user handles it according
to this manual.



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Citizen REF CT830 Ear Thermometer Instruction Manual

Citizen REF CT830







The ear thermometer must be inserted correctly to obtain correct temperature measurement. Be sure to consult a physician if you feel that your health is in poor condition.

DO NOT judge your health only on the presence or absence of a fever.

  1. Make sure that the probe lens is always clean.
  1. Very carefully and gently insert the probe into the ear.
  2. Avoid using the ear thermometer if there is inflammation on or in the ear.
  3. DO NOT use the ear thermometer if the main body is damaged (for example, the probe lens is broken). The continuous use of a damaged unit may cause injury, improper results, or serious danger. Contact a physician immediately if broken pieces are swallowed.

Protect the natural environment:

Please help protect natural environment by respecting national and/or local recycling regulations when disposing of the battery and the product at the end of their useful live.


If you dispose this product, do not dispose of with general household waste. There are separate collection systems for used electronics products in accordance with legislation under the WEEE Directive (Directive 2002/96/EC), effective only within European Union.



  1. The body temperature measured in the ear may differ from measurements taken under the armpits, in the mouth, or in the rectum. Therefore, comparing them will not be of value. Take temperature readings periodically to determine the normal ear temperature measurement with this instrument, then use that reading as the basis for comparison with any measurement taken when you suspect a fever.
  2. Do NOT use this thermometer for measurements other than as specifi ed. This thermometer is designed for ear measurement. Room temperature and material surface temperature readings are approximate and are only for reference.
  3. Do NOT immerse the ear thermometer in water or any other liquid and do NOT allow the unit to come into contact with chemical solvents.
  4. Do NOT drop the ear thermometer and do NOT expose the ear thermometer to heavy shock. The ear thermometer is not shock-protected.
  5. Do NOT bend the ear thermometer.
  6. Do NOT disassemble the unit, do NOT make any modifi cations to it, and do NOT touch the circuitry.
  7. Do NOT store the unit under the direct sunlight, do NOT store it at high temperatures, and do NOT store it in areas with a high degree of humidity and/or dust.
  8. Do NOT boil the probe.
  9. Do NOT use the ear thermometer if it operates irregularly or shows signs of malfunction.
  10. Do NOT use thinner or benzene to clean the ear thermometer.
  11. When removing the ear thermometer from storage at low temperatures, place it in a warm area for 5 to 10 minutes before use.
  12. Keep the ear thermometer out of the reach of children.
  13. Wipe the ear thermometer clean before storing.

About Ear Thermometers

All objects radiate heat. To measure body temperature, this ear thermometer uses an infrared sensor incorporated in its probe to detect the heat radiated from the eardrum and the area around it. In general the ear canal (external auditory canal) of an infant is relatively straight.

As we grow older, it takes on some curvature, as shown in Fig. 2. It is important to point the probe lens of the ear thermometer toward the eardrum and its periphery inside the ear. To straighten the ear canal, gently pull on the outer ear in the direction of the rear of the head, as shown in Fig.

Each ear canal has a slightly different shape, be sure to check it before taking temperature readings. Insert the probe straight into the ear canal, as shown in Fig. 4.

About Ear Thermometers


  1. A person’s left and right ear canals are not necessarily symmetrical. This may cause different measurement results. Always take temperature readings in the same ear.
  2. A soiled probe lens will result in inaccurate measurement. Be sure to check that the probe lens is clean before use.
  3. Body temperature rises after vigorous exercise, a bath or shower, or eating. Wait at least 30 minutes before taking temperature readings.
  4. Do NOT use the ear thermometer when the ear canal is wet (after swimming, bathing, etc.).
  5. Let the ear thermometer stand at room temperature before use.
  6. It is important to know your normal temperature so you can compare it to the measurement result.


This thermometer has the following functions for care of users.

  • Ear Temperature: for human temperature.
  • Time and calendar: for memory.
  • Room Temperature: for monitoring the ambient temperature for a baby or patient.
  • Material surface temperature (NOT for body temperature): for temperature of a baby’s milk, etc.
  • Stop watch: for taking a patient’s pulse.
  • Fever alarm: an alarm when a user’s temperature is more than 37.5°C, indicative of a fever.
  • Memory: for recording up to 9 temperature readings.
  • Celsius / Fahrenheit option switch: for international use.


  1. Press and hold the ON/MEM button for about 5 sec and the SET icon starts to fl ash, indicating the setting mode (Fig.5).

2. Press the SCAN button for the 12/24-hour setting mode. The 24 icon starts to fl ash, indicating the 24-hour display. Press the SCAN button again and the 24 icon will disappear from the screen, indicating the 12-hour display. When this display is used, afternoon times will be indicated with the PM icon. Press the SCAN button to toggle between the 12 and 24-hour displays.

3. Press the ON/MEM button to cycle the fl ashing icons in the
sequence below to select the respective setting.

hour-minute-year-month-day-leave the setting screen

While the setting section is fl ashing, press SCAN button to change the numbers. If no buttons are pressed in the setting mode for 8 seconds, the display automatically returns to the EAR TEMPERATURE mode.


  1. Make sure that the probe lens is clean.
  2. Press ON/MEM button and after the all indicators show up on the display (Fig.6), the ready message with icon displays, accompanied by two short beeps (Fig.7).

3. Gently pull the ear back to straighten the ear canal (Fig.3) and gently position the probe into the ear canal, aiming towards the membrane of the eardrum to obtain an accurate reading.

4. After the probe is positioned in the ear, press and hold the SCAN button until you hear one beep. The measurement is now complete. Remove the probe and read the temperature on the display (Fig.8).

Ear temperature mark

NOTE: The time and calendar settings should be done before measurement readings are taken. The thermometer always shuts off automatically in about one minute and the stand-by mode display (room temperature and date/time) will be shown. Without the time and calendar settings, the display will not show any indications after the thermometer shuts off. Pressing the buttons will NOT shut off the thermometer.


  1. Set the TIME AND CALENDAR FIRST. Then the stand-by mode display will appear after the automatic shut-off.
  2. When in stand-by mode, the room temperature will always appear on the display with the “Room temperature mark” icon (Fig.9).
Room temperature mark

3. The room temperature is renewed every minute. After measuring body or material surface temperature, the sensor may be warm which may affect the room temperature reading. Therefore during the fi rst 15 minutes after every use, the room temperature on the display may be inaccurate.


  1. Make sure that the probe lens is clean.
  2. Press ON/MEM button to enter the EAR TEMPERATURE mode.
    Press and hold the ON/MEM button and then press the SCAN button once to leave the EAR EMPERATURE mode and enter the MATERIAL SURFACE TEMPERATURE scan mode with ” Material surface temperature mark“icon (Fig.10).
Material surface temperature mark

3.1 Aim the probe toward the material and press the SCAN button, and the material surface temperature appears on the display. To measure the temperature of another material, repeat the procedure. If the SCAN button is pressed and held, the measurement reading will be continuously updated.
3.2 Applications include temperature measurements for water, milk, cloth, etc.

Press and hold the ON/MEM button and then press the SCAN button once to leave MATERIAL SURFACE TEMPERATURE mode and enter the STOPWATCH mode with the ” Stop watch mark” icon (Fig.11).


  • Do NOT submerge the probe tip in liquid.
  • This mode shows the surface temperature of material only and is NOT for taking human body temperature.


Stop watch mark

4.1 This mode counts from 0.01sec to 3 minutes.
4.2 To start and stop the stopwatch, press the SCAN button. To reset the counter, press the ON/MEM button.

Press and hold the ON/MEM button and then press the SCAN button once to leave STOP WATCH mode and return to the EAR TEMPERATURE mode.

If the thermometer detects a temperature over 37.5°C in the EAR TEMPERATURE mode, there will be a long beep followed by three short beeps to warn the user of a fever.

There are a total of 9 memory slots for recording EAR TEMPERATURE measurements. Each memory slot also records the date and time of the measurement. Memory slots can be cycled by pressing the ON/MEM button during the EAR TEMPERATURE mode (Fig.12).

Memory mark

NOTE: Even when a Memory slot is being displayed, users can measure ear temperature.


  1. Make sure the thermometer is in stand-by mode and indicating the room temperature, date, and time.
  2. Press and hold the SCAN button, then immediately press the ON/MEM button. After 3 seconds, the °C icon will switch to the °F icon. (use same procedure to switch back to °C).


If this unit is left unattended for about 1 minute, it will automatically power down from the current mode and enter the stand-by mode, showing room temperature, time, and date. The display alternates between time and date in a pattern that repeats every minute as follows: time 11 sec / date 4 sec / time 11 sec / date 4 sec / time 30 sec.


  1. Replace the battery when the display behaves as follows:
    The stand-by mode shows NOTHING on the display except the time and date. When the ON/MEM button is pressed, NOTHING is displayed except the battery mark blinking 12 times followed by OFF for 1 second and then the display returns to NOTHING except the time and date.

2. Insert a pointed object such as a pen into the battery cover access hole (Fig.13) while using your thumb to push the battery cover out.

battery cover out

3. Hold the device and pry the battery out with a small screwdriver (Fig.14).

battery out

4. Insert a new battery (CR2032) under the metal hook and press down on the battery until you hear a click. The positive (+) side should be up and the negative (-) side should be down.

5. Replace the battery cover.


  1. Remove and then reinstall the battery if the Er message is displayed, if the display is abnormal, or if nothing is displayed when the ON/MEM button is pressed.
  2. To protect the environment, dispose of the used battery according to local regulations.
  3. Remove the battery if the ear thermometer will not be used for a long time.
  4. Keep the battery away from children.


The probe is the most delicate part of the thermometer. Use caution when cleaning the probe lens to avoid damage.

Holding the thermometer too long may cause the probe to make a higher ambient temperature reading. This could make the body temperature measurement lower than usual.

  • After each use, clean the probe and probe lens with a cotton swab or soft cloth moistened with 70% alcohol.
  • Let the lens fully dry for at least 30 minutes.
  • Keep the unit dry and away from where it might be exposed to moisture, liquids, direct sunlight, high temperature, high humidity, or excessive dust.
  • Storing the thermometer at 10 to 40°C (50 to 104°F) allows you to measure body temperature at any time. Storing the thermometer below or above this temperature range may cause it to display Er 3. In such a case, leave the thermometer at 10 to 40°C (50 to 104°F) for at least 30 minutes before taking a measurement reading.



Questions and Answers

Q1: Why is temperature measured in the ear different from measurements taken under the armpit, in the mouth, or in the rectum?
A1: Temperatures of different parts of body may vary. Compare the measurement in question with a normal temperature previously taken in the same ear

Q2: The temperature differs each time I take a measurement. Why? What can I do?
A2: Your method for straightening the ear canal may be inconsistent, the way you insert the probe may be not consistent, or you may be taking a second measurement too soon. Pull the ear rearward to straighten ear canal, then very gently insert the probe into the ear canal for measurement. Once a measurement is taken, the temperature in the ear will be affected. Therefore, wait at least 1 minute before taking another measurement.

Q3: Can I measure temperature without the probe cover?
A3: This instrument is designed to measure temperature without the probe cover. Do NOT attach the probe cover or any film or covering.

Q4: Is it hygienically safe to use the ear thermometer without the probe cover?
A4: The probe and probe lens should be kept clean by using a cotton swab or soft cloth moistened with 70% alcohol. Therefore, the thermometer can be used hygienically without the probe cover.

Q5: Can I use the ear thermometer in cold/hot places?
A5: This instrument can be used in room temperature from 10 to 40°C (50 to 104°F). Error messages (Er 2 or Er 3) may be displayed if the temperature during storage greatly differs from that of the room temperature where you take a measurement reading. In such a case, let the ear thermometer stand for a while at room temperature before measurement.

Q6: Can I use the ear thermometer on an infant? Their ear canals are very small.
A6: Do NOT attempt to force the probe into the ear canal. Use caution and pay close attention while very gently inserting the probe just into the entrance of ear canal.

Q7: Can I use the ear thermometer to measure temperature under the armpit or in the mouth?
A7: No. This instrument is designed to measure temperature only in the ear.

Q8: Can I use the ear thermometer on animals?
A8: No. This instrument is designed to measure temperature in the ears of humans.



Attention: consult accompanying documents. Specifications may be changed without notice in the event of improvements being made.

Reference standard: Complies with ASTM E1965-98, EN12470-5: 2003
Clinical thermometers-Part 5: Performance of infra-red ear thermometers
(with maximum device), IEC60601-1-2(EMC), EN60601-1(Safety) standards.
Name: Radiant Innovation Inc.
Address: 1F, No.3, Industrial East 9th Road, Science-Based Industrial Park,
HsinChu, Taiwan 300.
European Representative:
Name: Medical Technology Promedt Consulting GmbH
Address: Altenhofstrasse 80, D-66386 St. Ingbert, Germany

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