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BT37 MarkII: Service Manual MA200606 1.0.0
Operation
duration is 540 seconds. Extended purge flow only occurs when both lids are shut and
starts when the user exits standby or bottle change mode. The flow then returns to
bleed flow.
2.2.1.1 Non-pulsed bleed flow
In non-pulsed mode, gas is provided at a steady rate defined by the Non-pulsed flow mL/
min setting. This is the default and recommended mode.
2.2.1.2 Pulsed bleed flow
In pulsed mode, the flow alternates between a low and high bleed flow rate. This requires
the Bleed off time s setting to be set to a non-zero value, otherwise non-pulsed flow will
be provided. In pulsed mode the flow is held at a low bleed rate for a duration defined by
the Bleed off time s and then at a high bleed rate for the Bleed on time s duration. The
low bleed rate is factory set to 20 mL/min and the high bleed rate to 60 mL/min.
2.3 Installing the humidifier
Caution
Use aseptic technique.
Do not re-use the bottles.
Do not use if packaging is broken.
Do not resterilize.
Do not refill the bottle.
The humidifier comprises a bottle, tube set and filter. A new humidifier will need to be
installed when the BT37 is first installed. The humidifier must be replaced every 30 days.
1. If there are samples in the BT37, transfer them to another unit.
2. From the main display, click Menu.
3. Select Bottle change. This will switch off the gas supply to the chambers.
4. The bottle change screen will be displayed along with the base temperatures.
5. Remove the existing bottle if fitted.
6. Install a new bottle. There are two bottle systems available for the BT37. Which one
is used can be determined from the seal fitted to the chamber lids.
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