User manual ROTOTHERM SERIES 33 RECORDER

[. . . ] 200 to 250 volts, 50 Hz (60Hz available); 100 to 110 volts, 50 Hz (60Hz available). Instruments without electrical control require no power supply provided that a clockwork drive is fitted. Battery operated chart drives require 1. 5 volt 'C' type cell. INTRODUCTION The RTO and RPO series of instruments are designed to measure, record and control process variables such as temperature, pressure and humidity. A maximum of three measuring systems can be provided in each instrument; a fluid expansion/gas expansion system is used for temperature recording, a wet and dry bulb system for humidity and a bourdon or diaphragm capsule for pressure measurement. [. . . ] Fit the chart onto the spindle of the clamp and rotate the chart until the pen tip is on the correct time line. Lower the chart clamp and press it firmly to ensure that the locating pips pierce the chart. Place the chart beneath the outer chart clips. SET POINT ADJUSTMENT (Fig. 5) For instruments fitted for Temperature Systems Disconnect Mains Power Supply For low alarm set point slacken the lock nut securing the low contact adjustment screw and screw the adjustment until the moving contact just makes contact with the low contact at the point required, the set point. For high alarm set point, slacken the lock nut, securing the high contact adjustment screw and screw the adjustment until the moving contact just makes contact with the low contact at the point required, the set point. Note: For the low alarm, unscrewing the adjustment reduces the set point and for the high alarm, unscrewing the adjustment increases the set point INKING SYSTEM The writing system uses the fibre pen capsules. A recess on the capsule fits onto the pen arm and the pen capsules are easily replaced when the ink is exhausted. To fit a capsule, pull the arm gently clear of its mountings, slide off the used capsule and replace it with a new one of the appropriate colour. Where there are two or more measuring systems, different colour inks are used to distinguish the traces. The fibre tip is protected by a plastic cap, which should be removed by pulling in line with its length, gripping the end only and gently twisting. The upper pen (red) has a long fibre Tip compared to the lower pen (blue) which has a short fibre tip. If the pen rests above the line, adjust the ranging screw (6) clockwise to bring the pen to the top of the chart. Return the bulb to the low temperature bath and adjust the zero nut (4 or 14) to bring the pen to the correct line. Check the top point and if still in error, repeat steps 4 and 5 until the bottom points are correct. Ease the pen arm boss (12) from the spindle taper and set the pen approximately 8 times the value of of the error on the opposite side of the mid-chart line. This adjustment is not possible on instruments fitted with differential contact mechanisms as the pen boss is factory set. Return the bulb to the low temperature bath and adjust the zero nut (4 or 14) to bring the pen to the correct value on the scale. If not correct, repeat step 8 (the multiple of 8 is a value, which in most cases, will correct the midpoint error). 4, position a centre punch in the hole in the centre of the pen arm boss (12) and with a 4 ounce hammer lightly applied, fix the boss on the spindle spear. Replace the pen arm and return the instrument to service. FOR INSTRUMENTS FITTED WITH TEMPERATURE SYSTEMS Warning Unless the range is such that the same liquid can be used in all baths the bulb should be wiped dry when transferring from one bath to another. This is particularly important when a "wide span" range; for example 0 to 450°C, where the "low point" bath would hold water and the "high point" bath fusible salts. In such a case, it is dangerous to insert a bulb wet with water into the salts bath. 3. Note In transferring from one temperature to another there will be a short time lag before the bulb reaches the bath temperature. [. . . ] · Any contamination on the bulb should be removed. 11. 12. Caution Before removing the bulb or pocket, ensure that the plant is shut down and the bulb is not under any pressure. 13. Zero Adjustment (For temperature Systems) If a careful check against a known and steady temperature shows the pen reading to be in error this can be corrected by means of the zero nut (4 or 12) shown in Fig 6. Other Adjustments If the zero error found above is large, the top value of the range should be checked after the zero error has been corrected. A small error in the span can be corrected by adjusting the ranging screw (6) clockwise to shorten the range or anticlockwise to lengthen the range. If the error is large, the measuring element is suspect and should be renewed. 7 MAINTENANCE REPLACING A FILLED SYSTEM Removal of a faulty system (Fig 6) 1. [. . . ]