Teledyne 200AH 用户手册

 

Green Off 

On Monitoring 
Blinking 

NOT monitoring, DAS disabled 
Monitoring normally, taking DAS data 
Monitoring, DAS in HOLDOFF mode

(1)

 

Yellow Off 

On 
Blinking 

AutoCal disabled 
AutoCal enabled 
Calibrating 

Red Off 

Blinking 

No warnings exist 
Warnings exist 

(1)

  This occurs during Calibration, DAS holdoff, after power-up and in Diagnostic mode. 

 

The power switch has two functions. The rocker switch controls overall power to the instrument, 
in addition it includes a circuit breaker. If attempts to power up the M200AH result in a circuit 
breaker trip, the switch automatically returns to the OFF position, and the instrument will not 
power up. 

The Power supply module supplies AC and DC power to the rest of the instrument. It consists of 
a 4 output linear DC power supply and a 15 volt switching supply. In addition, it contains the 
switching circuitry to drive the DC operated valves and several switched AC loads to operate the 
Rx cell heater, converter heaters and the ozone generator. The only voltages not generated in the 
PSM are the high voltage DC required by the PMT which is generated inside the sensor module 
and the high voltage AC used by the ozone generator. 

A standard M200AH comes with 2 valves, the NO/NO

X

 valve and the AutoZero valve, see 

Figure 4-2. Depending on the selected operating mode, the NO/NO

X

 valve: 

1.  NO only mode - routes sample gas continuously into the reaction cell. 

2.  NO

X

 only mode - routes sample gas continuously through the converter, then into the 

reaction cell. 

3.  NO/NO

X

 switching mode - switches gas alternately around, then through the converter to 

measure NO, NO

X

, and by calculation NO

2

. 

The AutoZero valve provides a continuous zero reference. Periodically, the valve switches to 
turn off sample gas to the reaction cell. The ozone continues to flow. The zero reading is 
averaged and used to compensate subsequent readings for PMT zero offset.