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7.2 ENTERING OR CHANGING THE PASSWORD [PASS]
If a password has been set, this must be entered before values can be changed. Note that the factory default password
is 0000.
1. Scroll DOWN to the PASS (Password) menu heading.
2. Press RIGHT: display shows ENTR (Enter). Press RIGHT again: the left-hand digit will start to flash.
3. Use the UP/DOWN keys to enter each digit in turn from left to right. Press RIGHT to move from one digit to the next.
4. After you have entered the 4th digit, press RIGHT again.
a) If you have entered an invalid password, the display will show BAD. Press RIGHT to re-enter your password.
b) If you have entered the correct password, the display will show GOOD. Press RIGHT. You will then be given the option
to alter the current password (display shows ALTR). Press RIGHT then enter a new password if required (otherwise
just keep pressing RIGHT to leave the password unchanged).
7.3 SENSITIVITY [SENS]
NOTE: The sensor sensitivity should be set before attempting to scale the instrument. If the sensitivity is adjusted at a
later stage, the instrument must be re-scaled.
The sensor has three sensitivities: High (default), Medium and Low. The first step to setting up the sensor is to set the
instrument to a sensible sensitivity level. The recommended procedure is to install the sensor and note the reading under
normal operating conditions.
HIGH sensitivity (default) – if the reading before scaling is between 0 and 100, leave on High sensitivity;
•
MEDIUM/LOW sensitivity – if the reading before scaling is >100, reduce to Medium or Low sensitivity.
•
7.4 DISPLAY SMOOTHING [DISP]
The display smoothing function allows a rapidly fluctuating dust reading to be 'smoothed out', thus providing a more stable
displayed value. The filter used is a walking window filter. Smoothing applied to the display is also used to calculate alarm
conditions for the alarm relays. The 4–20 mA output is smoothed independently via the 4–20 mA Settings menu.
7.4.1 Changing the Display Smoothing Filter
1. Enter the password, if required (see section 7.2 above).
2. Scroll DOWN to the DISP menu heading.
3. Press RIGHT: display shows FILT.
4. Press RIGHT again: display shows the filter time in seconds (default: 0005 = 5 s).
5. Adjust the value then press RIGHT to return to DISP.
NOTE on the range of allowed values –
FILTER: this is an integer value. Allows values between 1 and 9999 secs.
7.5 SCALING METHOD
7.5.1 Setting a Scaling Factor [SF]
The Scaling Factor [SF] is used to scale the raw dust reading to provide a mg/m³ reading within the instrument
(see section 7.1.1 on page 17 for the menu map). Alternatively, you may output the raw dust reading to your own
system (using analogue or Modbus outputs), then calibrate the reading within your system (see Appendix A –
Scaling on page 29). The SF scales the raw reading as follows:
The Scaling Factor [SF] is applied to the displayed reading. This is then used by analogue (4–20 mA) outputs.
Adjusting the Scaling Factor [SF]
1. Enter the password, if required (see section 7.2 above).
2. Scroll DOWN to the SF menu heading.
3. Press RIGHT: display shows the current scaling factor (default: 1.000)
4. Adjust each digit value using the UP/DOWN keys, then press RIGHT to move to the next digit.
5. After editing the 4th digit press RIGHT again: the decimal point starts to flash. Use UP/DOWN to adjust the
position of the decimal point.
6. Press RIGHT to return to the SF menu heading.
NOTE on the range of allowed values:
The default SF is 1.000. The range of allowed values is 0.001 to 9999.
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INSTALLATION AND OPERATION MANUAL – OWNER'S RECORD PEM MANUAL – PARTICULATE EMISSION MONITOR
Dust reading (mg/m³) = Raw instrument reading × SF
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