OPERATION MANUAL WALL-MOUNT CO 2 MONITOR Model: 7721 77231 7722 77232
INTRODUCTION Thank you for purchasing this wall mo unt CO 2 mo nitor. It me asures CO 2 level, air temp ., dew point, wet bulb temp . and humi dity(DP, WB , RH are for mo dels 7722/77232) and is an ideal instrume nt for indoor air quality (IAQ) diagnosis. Poor indoor air quality is considered unhealthy because it causes tiredness, loss of ability to concentrate, and even illness(ex. Sick Building Syndrome ).
MATERIAL SUPPLIED This package contains: Meter Adaptor Operation manual Plain white box Optional accessory: 33% calibration salt (VZ0033AZ1) 75% calibration salt (VZ0075AZ1) RS232 cable and software POWER SUPPLY The meter is powered by an AC adaptor (12V/1A output). LCD DISPLAY MAX MIN AVG TWA STEL PPM CO CO 2 CO 2 concentration in ppm ALM HLD Air temp. Dew point Wet bulb temp.
KEYPAD SET CAL ESC RESET DP/WB or MNX /AVG Enters setup mode. Saves and finishes settings. Enters CO 2 calibration with . Enters RH calibration with . Exits setup page/mode. Resets the meter and clear MAX/MIN. Terminates during calibration. DP/WB MNX /AVG Selects AIR, DP, WBT temps display. (7722/77232 only) Selects mode or increases value in calibration and setup. Activates MAX, MIN, STEL,TWA function. Selects mode or de creases value in calibration and setup.
TAKING MEASUREMENT The meter starts taking measurement after power on and updates readings every second. In the condition of opera -ting environment change (ex. from high to low temp.), it takes 30 sec to respond for CO 2 sensor and 30 minutes for RH. NOTE: Do not hold the meter close to faces in case that exhalation affects CO 2 levels. AIR (all models) ,DP,WBT (7722/77232) Press to switch temperatures display. The lower left display will cycle from air temperature, dew point temp. (Fig.
In STEL and TWA modes, the main display shows the weighted average of CO 2 readings for the past 15 minutes (STEL) and 8 hours(TWA). The lower displays are the current AIR, DP/WB temperatures and humidity (7722/ 77232). (Fig.6) STEL PPM CO 2 % O Fig.6 NOTE: 1. If the meter is turned on for shorter than 15 minutes, the STEL value will be the weighted average of readings taken since power on. Same for TWA values appear before 8 hours. 2.It takes at least 5 minutes to calculate STEL and TWA.
It emits beeps(Abt.80dB) with blinking LED when CO 2 level goes over the upper limit. Beeps can be stopped by pressing any key or automatically stops when CO 2 reading falls below lower limit. If the beeper is temporarily shut, it will sound again when readings fall below lower limit and then go over the upper limit again, or users press for more than 1 second to activate it. RESET LED alarm keeps blinking when beeps are manually shut. It stops only when readings fall under the lower limit.
SETUP Hold down under normal mode for more than 1 sec to enter setup mode. To exit setup, press in P1. 0, P3. 0, or P4. 0 and it returns to normal mode. SET CAL ESC Note: P2. 0 is not applicable in these models but for future model with CO and CO 2 measurements. P1.0 CO 2 ALARM: UPPER&LOWER LIMITS When entering setup mode, P1. 0 and “AL” (Fig.8) are displayed on the LCD. Press again to go into P1. 1 for setting CO 2 upper limit. The current set value will be blinking on LCD(Fig.9).
When the preferred value is set, press to go into P1. 2 (Fig. 10) for lower limit setting. After both settings are done, press to save or without saving and return to P1. 0 . SET CAL ESC SET PPM CO 2 Fig. 10 P3. 0 TEMPERATURE SCALE Press in P1. 0 to access P3. 0 for setting up temperature scale(Fig.11). Press and it goes into P3. 1 with blinking oC or oF current set(Fig.12) on the lower left display. To switch oC or oF, press or . Then press to save the setting or without saving and return to P3.
Press and it goes into P4. 1 with blinking “dis” default (Fig.14) on the lower left display. To enable the ABC function, press or and “En” blinks for choice(Fig. 15). After the preferred selection is done, press to save the setting or without saving and return to P4. 0 SET MNX /AVG DP/WB SET CAL ESC CO 2 CO 2 Fig. 14 Fig. 15 CO2 CALIBRATION The meter is calibrated at standard 400ppm CO 2 concentration in factory.
ABC (Automatic Baseline Calibration) ABC is to calibrate the meter at the minimum CO 2 reading detected during 7 days continuous monitoring (power on). It is supposed that the ventilating area can have fresh air with CO 2 level in around 400ppm during a period of time. It’s not suitable to implement ABC in close area with higher CO 2 level. The ABC default is off. To enable the function, please refer to SETUP P4.0.
RH CALIBRATION (7722/77232) The meter defaults to be calibrated the humidity with 33% and 75% salt solution. The ambient condition is recommended to be at 25 o C and stable humidity(better to be close to the calibrating value). To abort calibration, hold down for more than 1second at any time. RESET CAUTION: Do not calibrate the humidity without the default calibration salt. Otherwise, it will cause permanent damage. Contact the dealer for calibration salt or services.
O % Fig.19 “CAL” and calibrating value (75.2% if at 25 oC) are blinking on the LCD with current temperature at the left. Meter is now calibrating. Wait about 60 minutes until blinking stops, then calibration is completed and it returns to normal mode. NOTE: Users can also calibrate either point. To calibrate 33% only, press to exit when 33% calibration is completed. To calibrate 75% only, press or within 5 minutes while initializing 33% calibration. And it skips 33% and enters 75% calibration mode.
PC CONNECTION The meter can do PC link for on-line logging and data analysis via RS232 interface and software. The protocol is as follows. A.9600 bps, 8 data bits, no parity. B.Format ( ASCII) Model 7721/77231 Cxxxxppm:Txxx.xC(F) LRC CRLF Description: $CO 2 :Air LRC CRLF Model 7722/77232 Cxxxxppm:Txxx.xC(F):Hxx.x%: dxxx.xC(F):wxxx.
Appendix CO2 LEVELS AND GUIDELINES Non-Enforced Reference levels NIOSH recommendations 250-350 ppm: normal outdoor ambient concentrations 600 ppm: minimal air quality complaints 600-1000 ppm: less clearly interpreted 1000 ppm: indicates inadequate ventilation; complaints such as headaches, fatigue, and eye/throat irritation will be more widespread. 1000 ppm should be used as an upper limit for indoor levels.
