B873 - Wristwatch CITIZEN WATCH - Free user manual and instructions

Product Type	Professional 300m Diving Watch
Brand	CITIZEN WATCH
Model	B873
Caliber	B873
Movement Type	Analog quartz with 3 hands
Accuracy	±15 seconds per month (at normal temperature 5°C to 35°C)
Quartz Frequency	32 768 Hz
Operating Temperature Range	-10°C to +60°C
Main Functions	Display hours, minutes, seconds; date (depending on model); insufficient charge warning; quick start; time adjustment warning; overcharge protection
Power Reserve	Approximately 6 months from full charge; approximately 3 days from start of 2-second movement
Power Source	Light-charged secondary battery
Case	Titanium with surface treatment for hardness and scratch resistance
Rotating Bezel	With anti-reverse rotation mechanism
Crown	Screw-lock, positioned at 9 o'clock
Water Resistance	300 m (30 atm)
Strap/Bracelet	Metal, plastic or rubber; extension available for models BJ8040-01E and BJ8050-08E
Care and Cleaning	Clean with a soft cloth; for metal/plastic/rubber strap, use mild soapy water and a soft brush; avoid solvents
Safety	Do not use underwater if the crown is not properly screwed; do not expose to high temperatures (sauna, dashboard); avoid magnetic fields, strong shocks, chemicals
Repairability	Repairs must be carried out by a Citizen service center; the secondary battery does not require periodic replacement

Frequently Asked Questions - B873 CITIZEN WATCH

How do I set the time and date on my Citizen B873 watch?

To set the time, pull the crown to the second click (the second hand stops at 0 seconds), turn it to set the time, then push it back. For the date, pull the crown to the first click, turn it to set the date (avoid between 9 PM and 1 AM). Make sure to screw the crown back in after each adjustment.

What should I do if the second hand moves in two-second intervals?

This indicates insufficient charge. Expose the watch to light (ideally sunlight or under a fluorescent lamp). After sufficient recharge, the second hand will resume normal one-second movement.

How long does it take to fully charge the watch?

Charging time depends on brightness. Under summer sunlight (100,000 lux), full charge takes about 9 hours. In the shade on a cloudy day (10,000 lux), it takes about 33 hours. Under a fluorescent lamp at 20 cm (3,000 lux), expect 105 hours.

Can I use the watch for diving if the battery is low?

No, it is prohibited to use the watch for diving when the power reserve is insufficient (second hand moving at two-second intervals) or if the watch shows abnormal operation. Recharge it sufficiently before any dive.

How do I use the rotating bezel to measure elapsed time?

Turn the bezel (only to the left) to align the triangular mark with the minute hand. After a certain time, read the elapsed time on the bezel scale. For remaining time, align the mark with the target time.

What should I do if moisture has entered the watch?

If the glass is fogged up and does not disappear within a day, or if seawater has entered, place the watch in a box or plastic bag and take it immediately to a Citizen service center. Do not leave the watch in this condition, as corrosion may worsen.

How do I clean my Citizen B873 watch?

Use a soft cloth for the case and glass. For the strap (metal, plastic or rubber), wash it with mild soapy water and a soft brush. Avoid solvents like thinner or gasoline. If the watch is not water-resistant, have it cleaned by a professional.

Can I replace the battery myself?

No, the watch uses a rechargeable secondary battery that should only be replaced by a Citizen service center. Never use another battery (e.g., silver oxide), as it could overcharge and explode, damaging the watch and the wearer.

How do I adjust the strap length using the extension?

On models BJ8040-01E and BJ8050-08E, an extension is provided to wear the watch over a diving suit. Simply attach it to the existing strap to get the extra length needed.

What precautions should I take to avoid damaging the watch?

Avoid extreme temperatures (sauna, dashboard), magnetic fields (magnets, phones), strong shocks (drops), and chemicals (solvents, mercury). Do not pull the crown underwater and always screw it back correctly. After use in the sea, rinse with fresh water and dry.

USER MANUAL B873 CITIZEN WATCH

Request to Customers

All repairs performed on this watch, excluding repairs involving the band, are to be performed at the CITIZEN. When desiring to have your watch repaired or inspected, please contact the Citizen Service Center either directly or through the store where you purchased your watch.

Contents

1. Features of the Citizen Promaster 300 m Professional Diver 5
2. Names of Components 6 3.Before Using 7
3. Setting the Time and Date 8
4. Functions of Solar Powered Watches 10
5. Care and Handling During Charging 14
6. Replacing the Secondary Battery 15 8.Time Required for Charging 16
7. Do not Using this Watch While Diving when ... 18
8. When Using for Diving 19
9. Using the Rotating Bezel 21
10. Adjusting length with the Extension Band (Model No.BJ8040-01E, BJ8050-08E only) 23
11. Precautions 24
12. Specifications 30

1. Features of the Citizen Promaster 300 m Professional Diver

This watch is a diver's watch designed to withstand depths down to 300 m (water pressure equivalent to 30 atm).

1. Titanium Case Offering Outstanding Features

• The watch case employs a titanium base offering superior corrosion resistance, light weight and high strength, while the surface is specially treated for high hardness and enhanced scratch resistance.

2. Rotating Bezel with Reverse Rotation Prevention Mechanism to Prevent Incorrect Operation

• The rotating bezel, which is important for checking diving time, employs a reverse rotation prevention mechanism that prevents the rotating bezel from being rotated inadvertently.

3. Screw down locking Crown

• The screw down locking crown can be securely locked in position through the use of a screw-locking mechanism. What is more, the use of three O-rings results in enhanced airtightness and water resistance. Furthermore, the screw down locking crown is located at the 9:00 position to prevent it from obstructing movement of the wrist or wetsuit.

2. Names of Components

The design may vary depending on the model.

3. Before Using

This watch is powered not by an ordinary battery, but by converting photo energy to electrical energy.

Before using, expose to light and make sure the watch is sufficiently charged.

See "8. Time Required for Charging" for reference charging times.

A secondary battery is used in this watch to store electrical energy. This secondary battery is a clean energy battery which does not use any toxic substances such as mercury. Once fully charged, the watch will continue to run for about 6 months without further charging.

To use this watch comfortably, make sure that the watch is always recharged before it stops.

There is no risk of overcharging this watch. (Overcharge Prevention Function is provided)

We recommend that you recharge the watch everyday.

4. Setting the Time and Date

Note:

A screw down locking crown is employed to enhance the water resistance of the watch. When operating the crown, first turn it to the left to disengage the screw lock. Once you have finished operating the crown, always make sure to return the crown to the normal position and then turn it to the right while pushing it in so that the screw lock is securely engaged.

Setting the time

1. Stop the second hand at the 0 second position by pulling the crown out to the 2nd click.
2. Turn the crown to set the time.
3. After setting the time, firmly push the crown back in to its normal position.

Setting the date

1. Pull the crown out to the 1st click.
2. Set the desired date by turning the crown.
3. Do not adjust the date when the watch display is reading between 9:00 pm and 1:00 am, otherwise the date might not change on the following day.
4. In the case of date display models, turning the crown clockwise will result in the loose play of the crown.
5. The calendar function of this watch operates on a 31-day cycle. It is necessary to change the date to the first day of the following month manually by turning the crown for months having less than 31 days (months having 30 days and February.)
6. After you have set the date, be sure to firmly return the crown to its normal position.

5. Functions of Solar Powered Watches

If the charge becomes insufficient, a warning function will operate and the display changes as shown below.

If insufficient charge continues

Normal time display One second interval movement

If insufficiently charged If sufficiently charged

Insufficient charge warning display Two second interval movement

If insufficiently charged and time is set Hitch movement Time setting warning display The watch will begin to operate soon after it is exposed to light due to the Quick Start Function

Stop

If sufficiently charged and time is set

Insufficient Charge Warning Function

The second hand changes to a two second interval movement to indicate insufficient recharging.

Even in such a case, the watch keeps correct time, but about 3 days after the two-second interval movement begins, the watch will stop.

After exposing the watch to light, recharging takes place and the watch returns to one-second interval movement.

Quick Start Function

The watch will stop if it is completely discharged. It will begin to operate soon after it is exposed to light.

(However, the time to start may vary according to the brightness of the light.)

Two-second interval movement

Time Setting Warning Function

If the watch stops, subsequent exposure to light allows the Quick Start Function to start again, and the second hand moves with a hitch to indicate that the time is incorrect.

In this case, quickly recharge the watch and reset the time.

Otherwise, the hitch movement will continue.

Hitch movement

Overcharge Prevention Function

There is no risk of overcharging.

Once the secondary battery is fully recharged, the overcharging prevention feature comes into operation and prevents overcharging.

6. Care and Handling During Charging

Notes on use

Take care to charge your watch during use.

Please note that if you wear long sleeves, the watch can easily become insufficiently charged because it is hidden and not exposed to light.

• When you take the watch off, place it in as bright a place as possible, and it will always continue to run properly.

Notes on recharging

• Avoid recharging at high temperatures (over about 60°C / 140°F), otherwise the watch will be damaged during recharging.

(e.g.,) Charging the watch near a light source that easily becomes hot, such as an incandescent lamp or a halogen lamp.

Charging in a place that easily becomes hot, such as a dashboard.

When you charge the watch by an incandescent lamp, place the watch about 50 cm (20 in.) from the light source to prevent the watch from reaching an extremely high temperature.

7. Replacing the Secondary Battery

Unlike ordinary batteries, the secondary battery used in this watch does not have to be periodically replaced due to repeated charging and discharging.

CAUTION

Never use another battery different from the secondary battery used in this watch. The watch structure is designed so that a different kind of battery other than that specified cannot be used to operate it. In case a different kind of battery such as a silver battery is used, there is the risk of it becoming overcharged and bursting, causing damage to the watch and even to the wearer.

8. Time Required for Charging

Time required for recharging may vary according to the design (color of the dial, etc.) and operating environment. The following table will serve as a rough reference.

Illuminance (lux)	Environment	Time required
		One day usage	From the stop state to one second movement	Full charge time
500	Inside an ordinary office	3 hours	43.5 hours	—
1000	60-70cm (24-28in.) under a fluorescent light (30W)	1.5 hours	21.5 hours	—
3000	20cm (8in.) under a fluorescent light (30W)	30 minutes	7 hours	105 hours
10000	Outdoors, cloudy	10 minutes	2 hours	33 hours
100000	Outdoors, summer, sunny	3 minutes	36 minutes	9 hours

• The recharging time is the time when the watch is continuously exposed to light.

Full charge time: The time to fully recharge after the watch has stopped. One day usage: The time required for the watch to run for one day with one second interval movement.

9. Do not use this watch while diving when…

PROHIBITED

Do not use your watch while diving when the following occur.

• The insufficient recharging warning feature is activated. As the battery approaches the end of its life, the second hand begins to move in 2 second increments. (When this happens, expose the watch to light so that it recharges and the second hand returns to normal movement.)
• The watch stops or exhibits any abnormal operation.

10. When Using for Diving

Precautions when Using during Diving:

• When using a diver's watch, please make sure that you have received the proper education and training for various types of diving, and observe all rules.
• Please make sure to use the watch properly based on a thorough understanding of watch handling and precautions. Please note that failure to operate the watch in a manner not described in the user's manual may prevent the watch from functioning properly.

• Please make sure that the crown is pushed in firmly and the screw is securely tightened.
• Please check that the band is securely attached to the watch.
• Please confirm that there are no cracks, scratches, chips or other abnormalities in the band and glass.
• Please check that the rotating bezel rotates properly.
• Please check that the time and date are set correctly.
• Please check that the second hand is moving properly.

If the second hand is moving at two-second intervals, this means that the watch is not sufficiently charged. Sufficiently charge the watch when this occurs.

• Never attempt to turn or pull out the crown underwater. This can cause defective water resistance or other malfunction.
• Be careful to avoid bumping your watch on hard objects such as diving equipment or rocks.

• Completely wash off any sea water, mud or sand adhered to the watch with pure water after checking that the crown and screw are tightened. Wipe off any excess moisture with a dry cloth.

11. Using the Rotating Bezel

The rotating bezel can be used as a reference for elapsed time during diving or for the amount of time remaining relative to a predetermined amount of time.

[Setting the Rotating Bezel]

• Only turn the rotating bezel to the left. It cannot be rotated in the opposite direction (to the right) to prevent the risk of incorrect operation.

Determination of Elapsed Time

Turning direction

• Align the mark on the rotating bezel with the minute hand. After a certain amount of time has elapsed, the elapsed time can be determined from the scale on the rotating bezel.

Elapsed time

Determination of Remaining Time

Remaining time

• The remaining time can be determined by aligning the ∇ mark on the rotating bezel with the target time.

12. Adjusting length with the Extension Band (Model No. BJ8040-01E, BJ8050-08E only)

• When wearing the watch over a wetsuit and so forth, and the length of the standard band is not long enough, attach the extension band provided to adjust the length of the band.

13. Precautions

CAUTION: Water-resistance performance

There are several types of water-resistant watches, as shown in the following table.

The unit "bar" is roughly equal to 1 atmosphere.

• WATER RESIST(ANT) xx bar may also be indicated as W.R. xx bar.

For correct use within the design limits of the watch, confirm the level of water-resistance of your watch, as indicated on the dial and case, and consult the table.

Indication	Specifications
Dial or Case (case back)
DIVER'S WATCH 300M	Water-resistant to 300M

CAUTION

• Be sure to use the watch with the crown pressed in (normal position). If your watch has a screw-type crown, be sure to tighten the crown completely.
• Do NOT operate the crown with wet fingers or when the watch is wet. Water may enter the watch and compromise water-resistance.
• If the watch is used in seawater, rinse with fresh water afterward and wipe with a dry cloth.
• If moisture has entered the watch, or if the inside of the crystal is fogged up and does not become clear within a day, immediately take the watch to your dealer or Citizen Service Center for repair. Leaving the watch in such a state will allow corrosion to form inside.
• If seawater enters the watch, place the watch in a box or plastic bag and immediately take it in for repair. Otherwise, pressure inside the watch will increase, and parts (crystal, crown, buttons, etc.) may come off.

CAUTION: Keep your watch clean.

• Leaving dust and dirt deposited between the case and crown may result in difficulty in pulling the crown out. Rotate the crown while in its normal position, from time to time, to loosen dust and dirt and then brush it off.
• Dust and dirt tend to be deposited in gaps in the back of the case or band. Deposited dust and dirt may cause corrosion and soil your clothing. Clean the watch occasionally.

Cleaning the Watch

• Use a soft cloth to wipe off dirt, perspiration and water from the case and crystal.
• Use a soft, dry cloth to wipe off perspiration and dirt from the leather band.
• To clean a metal, plastic, or rubber watchband, wash away dirt with mild soap and water. Use a soft brush to remove dust and dirt jammed in the gaps in the metal band. If your watch is not water-resistant, take it to your dealer.

NOTE: Avoid using solvents (thinner, benzine, etc.), as they may mar the finish.

CAUTION: Operating environment

• Use the watch within the operating-temperature range specified in the instruction manual.

Using the watch where temperatures are outside the specified range, may result in deterioration of functions or even stoppage of the watch.

• Do NOT use the watch in places where it is exposed to high temperature, such as in a sauna.

Doing so may result in a skin burn.

• Do NOT leave the watch in a place where it is exposed to high temperature, such as the glove compartment or dashboard of a car.

Doing so may result in deterioration of the watch, such as deformation of plastic parts.

• Do NOT place the watch close to a magnet. Timekeeping will become inaccurate if you place the watch close to magnetic health equipment such as a magnetic necklace or a magnetic latch of a refrigerator door or handbag clasp or the earphone of a mobile phone. If this has occurred, move the watch away from the magnet and reset the time.
• Do NOT place the watch close to household appliances that generate static electricity. Timekeeping may become inaccurate if the watch is exposed to strong static electricity, such as is emitted from a TV screen.
• Do NOT subject the watch to a strong shock such as dropping it onto a hard floor.
• Avoid using the watch in an environment where it may be exposed to chemicals or corrosive gases.

If solvents, such as thinner and benzine, or substances containing such solvents come in contact with the watch, discoloration, melting, cracking, etc.

may result. If the watch comes in contact with mercury used in thermometers, the case, band or other parts may become discolored.

14. Specifications

1. Caliber No.: B873 2. Type: Analog Quartz Watch with 3 Hands 3. Accuracy: Within ±15 sec/month (within a normal temperature range of 5°C / 41°F to 35°C / 95°F) 4. Quartz oscillator frequency: 32,768 Hz 5. IC: C/MOS-LSI (1 pc.) 6. Operational temperature range: -10°C / 14°F to +60°C / 140°F 7. Display features: Time: hour, minute, second

Date: date (models with date display)

1. Additional features: Insufficient charge warning, Quick start, Time setting warning, Overcharge prevention
2. Continuous operating time: Approx. 6 months (from full recharge to stop) Approx. 3 days (from two second interval movements to stop)
3. Battery: Secondary battery

*Specifications are subject to change without prior notice.