Apollo IMY Integrator/Totalizer, Peak/Valley, Offset and Slope Display Temperature

offset = 150 - (146 x 1.0638) offset = 5.3

INTEGRATOR / TOTALIZER / PEAK / VALLEY / TEMPERATURE OFFSET (Optional)

INTEGRATOR/TOTALIZER

The integrator/totalizer option simply adds input readings together using a programmable time base and scaling coefficient. The decimal point position of the integrator/totalizer can be programmed independent of the scaled input signal. The integrator/totalizer may be reset through a remote input, by the front panel or through the serial communications option. Alarms may be programmed to trigger from integrator/totalizer values; for example to total “degree minutes” for batching operations. The programmable time bases are “per second”, “per minute” and “per hour”, meaning the integrator/totalizer will accumulate at a fixed rate of 2 12 times per second and be equal to a fixed input level over the selected time period. For example, if the input is a constant 100￿ and the “per minute” time base is selected, the integrator/totalizer will accumulate at the rate of 100￿ per minute. The totalizer is updated at this rate every 400 msec. As a result, the input is accumulated in “batches” of 6.6 counts every 400 msec. Therefore, the totalizer start and stop sequencing, as well as alarm values set for triggering at specific totalizer values, are only accurate to the 400 msec totalizer update rate. The preceding example requires a scale factor of 1.000 to yield exact time bases, but any scale factor can be used to span between the ranges. (See section on integrator/totalizer programming for detailed information.) A programmable low temperature level disable feature completes the integrator/totalizer features (this will stop totalization when the input drops below this programmed value, “low cut”). At loss of power to the indicator, the contents of the integrator/totalizer is saved. This will allow integrating/totalizing of interrupted processes. The total can accumulate to 999,999. If the low-end cut-out value is programmed negative (ex. -100, reference Program Module #5), and the input display value is between zero and the low-end cut-out value, the totalizer value will decrement. If the input display value goes above zero the total will increment. If the display value goes below (more negative than), the low-end cut-out value, totalization will stop.

PEAK/VALLEY

The other features of the integrator/totalizer option are peak and valley detection. The indicator will record the lowest reading (valley) and the highest reading (peak), automatically, for later recall. This information is

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valuable in monitoring the limits of the process over any length of time since these values are stored at power-down to span over shifts, days, etc. An external input can be programmed to reset or engage the unit into a peak/valley reading indicator. Additionally, the peak and valley can be viewed and reset from the front panel, if so programmed, and viewed and reset from the serial communication option.

Note: The peak/valley measurement is not instantaneous, and is based on a nominal 2 sec. response time.

OFFSET AND SLOPE DISPLAY TEMPERATURE

If a difference exists between the displayed temperature and a reference temperature point, the display may be offset for this effect. Similarly, a correcting “slope” may be programmed, with the offset, to allow for two point temperature correction.

For most applications, the slope and offset values are not changed. But if it is required to scale the display to match a calibrated probe, the following formula and example show the calculation of appropriate slope and offset values.

Desired Display = (slope x actual temp. display) + offset slope = difference of two desired temperature points difference of two actual temperature points offset = one desired temperature point - (slope x one

corresponding actual temperature point)

Example:

The meter is displaying 52 degrees and 146 degrees (actual temperature) when the calibrated temperature reference shows that 50 degrees and 150 degrees respectively should be displayed (desired temperature).

First determine the new slope value using the sets of temperature points. slope = 150 - 50 = 100 = 1.0638

146 - 52 94

Next, determine the new offset value by using either one of the temperature pairs.