Bacharach 2772-0803 manual Excessive Tape USE, Tape Breakage, Light Faults, Door Fault

REMOTE INTELLIGENT SENSOR - AREA MONITOR

NOTE: The sections below do not refer to the modest changes in flow that occur over a period of time and are quickly adjusted for with the appropriate potentiometer.

4.20.1A FAULTY PUMP. If this is the case, change the pump. Note that there are two pump types, which are fitted depending upon the RIS model. Refer to Sections 4.8 & 4.11 for guidance including typical pump running current. Check Section 5 for the correct catalog number.

4.20.2A BADLY FITTED INPUT TUBE. Check to ensure that the input tube(s) is correctly fitted and that no leakage is occurring.

4.20.3A FAULTY TAPE GATE SEAL. This problem is only likely after several years operation. It can occur through distortion, or wear, of the seal as a result of the opening and closing of the gate over an extended period. Replacing the seal re- quires special knowledge, and should be referred to one of our Service Centers.

4.20.4LEAKING OR LOOSE TUBING. Check to ensure that all of the pipe work in the mechani- cal chassis is sound and properly connected.

4.21 EXCESSIVE TAPE USE

Cassettes lasting appreciably less than 30 days may be due to:

4.21.1MONITORED CONCENTRATION LEVELS HIGH. During periods when significant levels are monitored, the system will use each track only once; it will also operate in the ‘time mode’ if the sample concentration is high enough. Both conditions will increase tape consumption.

4.21.2EXCESSIVE STEP LENGTH. This can occur because an undue amount of tape is pulled through the gate at each step. The average step length should be 0.027" to 0.032" (7 to 8 mm) and the method of measuring it is described in Section

4.10.6.This condition, if present, may be caused by high take-up clutch torque, a weak pinch roller arm spring, a maladjusted tape gate, or a combination of these factors. Rectification is considered a Service Center repair.

4.22 TAPE BREAKAGE

Tapes can be damaged by careless insertion of a new cassette. Take care, as it is difficult to repair a broken tape. If the tape breaks during normal operation check that the tape is not damp which would reduce its strength. Tape breakage can also occur if the tape gate gap is too small. If this is the case, the take-up clutch will pull against the con- straints of the gate causing the tape to break. The tape-gate gap can be checked as in Section 4.10.6.

If the two ends of a broken tape can be ‘fished out’ of the cassette body they can be repaired by careful joining with adhesive tape. The join must then be completely wound onto the take-up spool so that it does not pass through the tape gate when operation resumes.

CAUTION

Do not touch tape with bare fingers to avoid contact with chemicals on the tape.

4.23 LIGHT FAULTS

If Light Faults occur, check (in the TEST Mode) that the light level values are at, or close to 220. If not, adjust as covered in Section 4.4. Make sure when adjusting that the tape in the gate, when the adjustment is made, is clean and not stained.

If the light level when checked is found to be correct at, or close to, 220 make sure that it is not possible that some external bright light (natural or artificial) does not shine directly up the input tube(s).

Remember that opening the tape gate without putting the system into the TEST Mode can cause a light fault as well as a spurious gas alarm.

If no apparent reason for frequent light faults is found refer to one of our Service Centers for assis- tance.

4.24 DOOR FAULT

If the door fault is intermittent or the door needs excessive tightening of the screws to turn it off, or if it cannot be turned off, adjust the switch. This is covered in Section 4.7.

Page 4-8 Instruction 2772-0803