The majority of plantations in Indonesia are familiar with Ombrometer or commonly referred to as ombro. In simple terms, ombro is used to measure rainfall in an area within a certain period. Generally, the reading of the rainfall data is carried out every morning. The measurement method is to open the faucet on the ombrometer and collect water from the measuring cup.
Infield, rainfall data measurement using ombro has various challenges. First, plantation areas with an area of more than 3000 ha generally have more than 1 measuring point so that ombro installment should be extended and quite far from the office. Weather factors such as rain and wind can be a challenge for the team in charge of observing it. Second, the results of measurements using Ombro are recorded manually, so there is a risk of being lost, damaged, or even (which is very unexpected) manipulated. In addition, if you want to know the rainfall on the D day, then the operational section needs to wait for the next day or H + 1 to collect data. The length of time to gain insight into the rainfall in field with ombro can be explained in the following flow:
Observation on site -> trip of observation point to garden office -> data input to computer -> data processing -> rainfall insights
In February 2019, one of the oil palm plantations in Palembang collaborated with Mertani to apply automatic rainfall monitoring technology. This technology is known as Automatic Rainfall (ARF). This ARF is applied as a substitute for Ombro at 2 observation points, one of which is near the field office. As a first step, ARF was installed near Ombro to compare measurement results. This process is known as the tool calibration process.
At the start of the calibration process, the data generated by ARF may differ slightly from Ombro. This is normal because there are differences in environmental conditions between ARF when it is planted in comparison to quality control (QC) by the Mertani team in Yogyakarta (production house). After the calibration is carried out, the measurement data generated by the ARF can be closer to the Ombro measurement data. However, this data can be directly observed via a PC or smartphone. Apart from that, the data can also be downloaded at any time if you need to process the data to do reports, get insights, and determine the garden management policy.