MST 5700 - Det Ect or O Pen Circu It; Display will Not Read Upscale; Display Goes off Scale; D Isp la y G Oe S B Elo W 0

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MODEL 5700
c) At 5.8 volts the buzzer will beep at 1-second intervals and the display will
go to --. This malfunction indication will continue until the battery is
completely dead.
2. Detector (cell) open circuit
If there is a discontinuity in one or more of the detector leads, or internal to the
cell itself, the following malfunction indications will occur:
Open Wire
Green Pilot Amber Light Red Light Buzzer Display
Red (SENS) pulsing off pulsing pulsing SC
Black(CNTR) pulsing off pulsing pulsing SC
Blue (REF) off off steady steady +1 or 199
All pulsing off pulsing pulsing SC
3. Display will not read upscale.
If the display will not move from zero (00) when detector is exposed to sample of
CO:
a) SPAN adjustment set to zero--recalibrate SPAN and set ZERO.
b) Cell has lost sensitivity--replace cell.
c) Circuit malfunction--repair is needed.
4. Display goes off scale (1).
a) CO concentration greater than 199 ppm.
b) REF wire disconnected or cell has internal failure.
c) Circuit malfunction; repair is needed.
5. Display goes below 0 (-02,-1 or SC).
a) ZERO misadjusted--readjust as in paragraph III. -A-1 through 5.
b) SENS, CNTR or all wire(s) disconnected or cell has internal failure.
c) Circuit malfunction--repair is needed.